FindLibClang.cmake: add 3.6 version support

http://llvm.org/apt/ provides 3.6 now that LLVM 3.5 has been released.
irony.el: update version header, release 0.1.1

This release contains bug fix and performance improvements, important changes are:

* Improve completion performances
* Build fixes for irony-server on Mac OS X
* Update FindLibClang.cmake to support new release of Clang
FindLibClang.cmake: support 3.5.0 release in addition to 3.5

On Arch Linux the version used is 3.5.0 while on Ubuntu/Debian (from
http://llvm.org/apt/) the version used is 3.5.

Fixes #126.