ANGLE: upgrade to 2.1~07d49ef5350a

This version of ANGLE provides partial ES3 support, numerous
bug fixes, and several potentially useful vendor extensions.

All patches have been rebased. The following changes are noted:

0000-General-fixes-for-ANGLE-2.1.patch
  contains compile fixes for the new ANGLE

0004-Make-it-possible-to-link-ANGLE-statically-for-single.patch
  has incorporated patch 0015.

0007-Make-DX9-DX11-mutually-exclusive.patch
  has been removed as it was fixed upstream.

0007-Fix-ANGLE-build-with-Microsoft-Visual-Studio-14-CTP.patch
  has been moved up to fill the patch number gap.

0010-ANGLE-Enable-D3D11-for-feature-level-9-cards.patch
  now contains patch 0014 and 0017.

0013-ANGLE-Allow-for-universal-program-binaries.patch
  has been removed as it is no longer relevant.

0014-ANGLE-D3D11-Fix-internal-index-buffer-for-level-9-ha.patch
  has been merged with patch 0010.

0015-ANGLE-Don-t-export-DLLMain-functions-for-static-buil.patch
  has been merged with patch 0004.

0016-ANGLE-WinRT-Call-Trim-when-application-suspends.patch
  has been removed and will be replaced by a follow-up patch using a
  different technique.

0017-ANGLE-D3D11-Don-t-use-mipmaps-in-level-9-textures.patch
  has been merged with patch 0010.

0018-ANGLE-WinRT-Create-swap-chain-using-physical-resolut.patch
  has been removed and will be replaced by a follow-up patch extending
  the EGL_ANGLE_window_fixed_size extension.

0019-Fix-ANGLE-build-with-Microsoft-Visual-Studio-14-CTP.patch
  is now patch 0007.

[ChangeLog][Third-party libraries] ANGLE has been upgraded to
version 2.1, bringing partial support for OpenGL ES3 over
Direct3D 11, numerous bug fixes, and several new vendor extensions.

Change-Id: I6d95ce1480462d67228d83c1e5c74a1706b5b21c
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>