Open folder dialog style change to Macish(cherry picked from commit 5174c552)

(cherry picked from commit b0e23fc3)

(cherry picked from commit 553a3a75)

(cherry picked from commit c152ecb5)

Conflicts:

	plugins/github/src/org/jetbrains/plugins/github/GithubRebaseAction.java

IDEA-63508 Github integration: share project on github works incorrectly for maven multimodule projects
(cherry picked from commit 2d99831b)

(cherry picked from commit a723acc1)

(cherry picked from commit 656cf42f)

when opening a file via PlatformProjectOpenProcessor, look for .idea in directories above it (PY-2562)

always open file from command line through OpenFileDescriptor to make sure file associations dialog is called if needed (PY-2565)

(cherry picked from commit 5152b292)

Defined 2 specialties for CYGWIN.
Don't start cygwin via runnerw, because runnerw doesn't pass parameters to cygwin Git (the reason of this is under investigation).

GitVersion: checking for version only on plugin activation and when changing the executable. Identifying current version by using a direct CapturingProcessHandler without going into GitHandler procedure.

Parsing rewritten on the Pattern.
Note that equals, hashCode and compareTo are intentionally not consistent now.
GitVersionTest for parsing, equals and compareTo.