Formatting Tool Employed

The formatting tool astyle has been employed over the software. A target for
formatting has been added to the Makefile to automate this process with
specific command line options. .gitignore has been updated to reflect these
changes so as to not add the original tabbed files (marked *.orig by astyle).

File(s):
   modified:   .gitignore
   modified:   Makefile
   modified:   include/linkedlist.h
   modified:   include/queue.h
   modified:   src/linkedlist.c
   modified:   src/queue.c