add Cirru with some samples

Cirru is a set of grammar rules designed for scripting langauges based on indentations.
Home page: http://cirru.org/

Pygments support merged but not released:
https://bitbucket.org/birkenfeld/pygments-main/pull-request/275/add-syntax-for-cirru/diff
Syntax support of Ace editor not merged yet: https://github.com/ajaxorg/ace/pull/1780
I'm not sure when they are possible to be run on GitHub, so I commented them by now.