closes quicksurf/quicksurf-bash-utilities#1

This changeset checks to see if a git script is currently in a git
before performing the git commands it is supposed to perform.

If not currently in a git repo, then the script is exited with a status
code of 1.

	modified:   add
	modified:   commit
	new file:   ig
	modified:   log
	modified:   master
	modified:   pb
	modified:   pull
	modified:   push
	modified:   status
	modified:   wip