Correct some UI text typos

Thanks to Christoph, DF7CB, for providing a patch for these typos.

Configuration.ui

@@ -951,7 +951,7 @@ a few, particularly some Kenwood rigs, require it).</string>
           <item row="0" column="1">
            <widget class="QRadioButton" name="PTT_DTR_radio_button">
             <property name="toolTip">
-             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Use the RS-232 DTR control line to toggle your radio's PTT, requires hardware to inteface the line.&lt;/p&gt;&lt;p&gt;Some commercial interface units also use this method.&lt;/p&gt;&lt;p&gt;The DTR control line of the CAT serial port may be used for this or a DTR control line on a different serial port may be used.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Use the RS-232 DTR control line to toggle your radio's PTT, requires hardware to interface the line.&lt;/p&gt;&lt;p&gt;Some commercial interface units also use this method.&lt;/p&gt;&lt;p&gt;The DTR control line of the CAT serial port may be used for this or a DTR control line on a different serial port may be used.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
             </property>
             <property name="text">
              <string>&amp;DTR</string>
@@ -982,7 +982,7 @@ other hardware interface for PTT.</string>
           <item row="1" column="1">
            <widget class="QRadioButton" name="PTT_RTS_radio_button">
             <property name="toolTip">
-             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Use the RS-232 RTS control line to toggle your radio's PTT, requires hardware to inteface the line.&lt;/p&gt;&lt;p&gt;Some commercial interface units also use this method.&lt;/p&gt;&lt;p&gt;The RTS control line of the CAT serial port may be used for this or a RTS control line on a different serial port may be used. Note that this option is not available on the CAT serial port when hardware flow control is used.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Use the RS-232 RTS control line to toggle your radio's PTT, requires hardware to interface the line.&lt;/p&gt;&lt;p&gt;Some commercial interface units also use this method.&lt;/p&gt;&lt;p&gt;The RTS control line of the CAT serial port may be used for this or a RTS control line on a different serial port may be used. Note that this option is not available on the CAT serial port when hardware flow control is used.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
             </property>
             <property name="text">
              <string>R&amp;TS</string>
@@ -1080,7 +1080,7 @@ or bandwidth is selected).</string>
           <item row="0" column="2">
            <widget class="QRadioButton" name="mode_data_radio_button">
             <property name="toolTip">
-             <string>If this is availabe then it is usually the correct mode for this program.</string>
+             <string>If this is available then it is usually the correct mode for this program.</string>
             </property>
             <property name="text">
              <string>Data/P&amp;kt</string>

widgets/mainwindow.ui

@@ -1,3 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
  <class>MainWindow</class>
@@ -981,7 +982,7 @@ QPushButton[state=&quot;ok&quot;] {
          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Select operating band or enter frequency in MHz or enter kHz increment followed by k.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
         </property>
         <property name="accessibleName">
-         <string>Frequncy entry</string>
+         <string>Frequency entry</string>
         </property>
         <property name="accessibleDescription">
          <string>Select operating band or enter frequency in MHz or enter kHz increment followed by k.</string>
@@ -2635,10 +2636,10 @@ list. The list can be maintained in Settings (F2).</string>
                       <item>
                        <widget class="QCheckBox" name="WSPR_prefer_type_1_check_box">
                         <property name="toolTip">
-                         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;6 digit locators cause 2 different mesages to be sent, the second contains the full locator but only a hashed callsign, other stations must have decoded the first once before they can decode your call in the second. Check this option to only send 4 digit locators if it will avoid the two message protocol.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+                         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;6 digit locators cause 2 different messages to be sent, the second contains the full locator but only a hashed callsign, other stations must have decoded the first once before they can decode your call in the second. Check this option to only send 4 digit locators if it will avoid the two message protocol.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
                         </property>
                         <property name="accessibleDescription">
-                         <string>6 digit locators cause 2 different mesages to be sent, the second contains the full locator but only a hashed callsign, other stations must have decoded the first once before they can decode your call in the second. Check this option to only send 4 digit locators if it will avoid the two message protocol.</string>
+                         <string>6 digit locators cause 2 different messages to be sent, the second contains the full locator but only a hashed callsign, other stations must have decoded the first once before they can decode your call in the second. Check this option to only send 4 digit locators if it will avoid the two message protocol.</string>
                         </property>
                         <property name="text">
                          <string>Prefer type 1 messages</string>