updated VERSION for 2.1.7
bumped Symfony version to 2.1.8-DEV
bumped Symfony version to 2.2.0-RC2-DEV
[HttpKernel] fixed the creation of the Profiler directory
Merge branch '2.1' into 2.2

* 2.1:
  [HttpKernel] fixed the creation of the Profiler directory
  [Security] fixed session creation when none is needed (closes #6917)
  [FrameworkBundle] removed obsolete comment (see 2e356c1)