This commit adds the new send-message command for sending messages.
This also redoes the logging of sent/rx'd packets to a single method
which is syncrhonized, so we don't get intermixed log messages for
packets.
Also adds email address validation during startup, and
optionally disables the validation via a command line switch. without
email validation for production running aprsd, emails sent can turn up
garbage and cause issues when those emails are received by aprsd
message processing as invalid content.
This branch refactors the majority of main.py out into individual
modules to compartmentalize the code. Migrated all email related
features unti email.py, sending of messages into messaging.py
Also refactored all of the socket code to use aprslib for all APRS-IS
communication as well as message/packet processing.
Moved the email command into it's own Plugin.
This patch reworked the loading of plugins. Python2 is dead.
Previously was using the imp module to easily load the plugins from
a separate directory, which is a bit of a pita. Found a python3 lib
that takes care of the difference between py3.3, 3.4 and 3.5+ module
loading called "thesmuggler"
