FileHandler should not be called for files outside the root

FileHandler#matches? should return false for files that are outside the
"root" path.

Conflicts:
	actionpack/lib/action_dispatch/middleware/static.rb
bumping version to 4.1.7
Merge branch '4.1.7' into 4-1-stable

* 4.1.7:
  bumping version to 4.1.7
  FileHandler should not be called for files outside the root