A step towards stable.
Created colors.sh for easy coloring of system outputs.
Created utils.sh with convenience methods for success, warning and regular system prints.
Updated help texts.
Added target_branch functionality for 'gs done'.
'gs dev' now ensures uniqueness of branch name and pushes the new branch to remote.
'gs dev' now ensures existence of base_branch.
'gs done' checklist output colored orange.
Merge branch 'master' of github.com:buren/git-story

Readme merge.