Get rid of jt9com and npar common blocks

Also  use correct  C binding  and have  compilers determine  sizes and
offsets.

The wsjtx.exe program now owns the  decoder shared data that is shared
with symspec.  It is now in  struct dec_data, still a  global variable
for now but hopefully a MainWindow member variable soon.

The struct  dec_data (in both C/C++  and Fortran) has a  sub structure
with the decoder  parameters which enables copying  and manipulating a
lot cleaner.

New  of  changed types  of  shared  data  must  still be  modified  in
commons.h and a  new file lib/jt9com.f90, they must stay  in sync as a
pointer to the structure is passed between C and Fortran.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6290 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

main.cpp

@@ -28,6 +28,7 @@
 #include "SettingsGroup.hpp"
 #include "TraceFile.hpp"
 #include "mainwindow.h"
+#include "commons.h"
 #include "lib/init_random_seed.h"
 
 namespace
@@ -181,16 +182,12 @@ int main(int argc, char *argv[])
       mem_jt9.setKey(a.applicationName ());
 
       if(!mem_jt9.attach()) {
-        if (!mem_jt9.create(sizeof(jt9com_))) {
+        if (!mem_jt9.create(sizeof(struct dec_data))) {
           QMessageBox::critical (nullptr, "Error", "Unable to create shared memory segment.");
           exit(1);
         }
       }
-      char *to = (char*)mem_jt9.data();
-      int size=sizeof(jt9com_);
-      if(jt9com_.newdat==0) {
-      }
-      memset(to,0,size);         //Zero all decoding params in shared memory
+      memset(mem_jt9.data(),0,sizeof(struct dec_data)); //Zero all decoding params in shared memory
 
       unsigned downSampleFactor;
       {