- Copy stable/10@285827 to releng/10.2 in preparation for 10.2-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.2.
- Update default pkg(8) configuration to use the quarterly branch.[1]

Discussed with: re, portmgr [1]
Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Bring the contrib/llvm/patches directory up-to-date.

MFC r263892:
Add the llvm/clang patch for r263891.

MFC r264350:
Update the llvm/clang patch for r264345.

MFC r266675:
Add the clang patch for r266674.

MFC r275651:
Add llvm patch corresponding to r275633.

MFC r275747:
Update llvm patches for r274286 and r275633 so all the tests will pass.

MFC r275760:
Add clang patch corresponding to r275759.

MFC r275772:
Update clang patch for r275759 to use correct test cases.

Additionally:
* Remove the clang patch corresponding to r263619, as ARM EABI
hard-float support was never MFC'd.
* Add clang patch corresponding to r279302.