Add the branch's dirty state to the prompt.

Based on:
http://bytebaker.com/2012/01/09/show-git-information-in-your-prompt/

README.md

@@ -26,6 +26,8 @@ Edit your  `~/.profile` or `~/.bash_profile` and add the following to the top:
 
     export GITAWAREPROMPT=~/.bash/git-aware-prompt
     source $GITAWAREPROMPT/main.sh
+    export PS1="\u@\h \w\[$txtcyn\]\$git_branch\[$txtylw\]\$git_dirty\[$txtrst\]\$ "
+
 
 Optionally, if you want a nice pretty prompt when using `sudo -s`, also add this line: