Update main.c

Cleaning up handle_minute_tick.  Moved static char arrays to file scope as it makes more sense to have these variables file scope.  Changed some static char arrays to const char arrays because they will never change.  Changed text manipulation to better make use of the standard library.
Merge pull request #2 from slice27/develop

Update main.c
changing hours remaining text

it now says "4 hours left" instead of "04 hours left"
Merge branch 'develop' of github.com:obihann/Beer-O-Clock

* 'develop' of github.com:obihann/Beer-O-Clock:
  changing hours remaining text
  Update main.c