Fix MSVS 2013 generator to use correct version numbers

R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/19802007

git-svn-id: http://gyp.googlecode.com/svn/trunk@1680 78cadc50-ecff-11dd-a971-7dbc132099af
xcode_emulation: added support for -fobjc-arc

This is needed for projects that want to use ARC
(http://clang.llvm.org/docs/AutomaticReferenceCounting.html)

Note that using ARC has implications on where your binary
can run; see  for details (or be happy with restricting to
OS/X 10.8+ and iOS 6.0+).

BUG=https://code.google.com/p/webrtc/issues/detail?id=2106
TESTED=git try, works in libjingle
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/19708002

git-svn-id: http://gyp.googlecode.com/svn/trunk@1681 78cadc50-ecff-11dd-a971-7dbc132099af
Add msvs_emulation expansion for $(TargetName) and $(TargetDir)

* $(TargetDir) is equivalent to $(OutDir)
* $(TargetName) logic is taken from the logic that sets 'TargetName' in
  generators/msvs.py

R=scottmg@chromium.org
BUG=

Review URL: https://codereview.chromium.org/19660003

git-svn-id: http://gyp.googlecode.com/svn/trunk@1682 78cadc50-ecff-11dd-a971-7dbc132099af