Added fn_tmuxcheck for all the special people who do not know how to
RTFM or use Google then leave a comment asking what 'tmux: command not
found means' I'm not bitter...honest!
* Major changes to terminal and log messages.
* More constant and improved wording of terminal and log messages.
* New local variable "modulename" that is displayed in terminal and log
messages.
* Added commented descriptions to most functions.
This moves all the defining functions to its own file and out of the
main script file. This has made the main scrip file much smaller and
moved most code to the functions dir