Bump folly to 4:0
Don't try to use gflags
Bump folly to 5:0
Add io/async back into folly build
Make thrift a submodule

Summary: This diff makes thrift a submodule, instead of copypasta'ing it in.

CMake only builds the stuff needed under thrift/lib/cpp (probably still more than hhvm needs).

Test Plan: built hhvm.

Conflicts:
	folly/CMakeLists.txt
Merge pull request #34 from djwatson/master

Make thrift a submodule
Backported thrift warning fixes, bump thrift submodule hash

Also removed a couple more not-needed-by-hhvm dirs from cmake
Merge pull request #35 from djwatson/master

Backported thrift warning fixes, bump thrift submodule hash
Rebase on top of proxygen/lib/services changes - some files were moved from proxygen->folly
Merge pull request #37 from djwatson/master

Rebase on top of proxygen/lib/services changes
Revert "Don't remove compilation of FunctionalExcept.cpp on libc++"

This reverts commit d1d591b86a771fba3f1410a1686dfdd52bd89407.

It breaks compilation on Ubuntu 12.04.
Revert "Rebase on top of proxygen/lib/services changes - some files were moved from proxygen->folly"

This reverts commit 6dc76d14134be66a704c2a18677d3e90812c2c87.
Revert "Revert "Rebase on top of proxygen/lib/services changes - some files were moved from proxygen->folly""

This reverts commit 5975e8d3cd64c379961e7145bdd1462fc22f5dc5.
update folly to hash to point to 12:0 and help fix the HHVM OSS build
Update folly submodule to version 13:0
Enable folly/LifeSem.cpp and folly/detail/Futex.cpp build.

These used to not build right, but they seem okay now.
Needed for asio thread manager.
Enable folly/detail/MemoryIdler.cpp build.
Bump thrift to 12:0
Revert "Bump thrift to 12:0"

This reverts commit 4e1c7368825b91e8e5f03df331a4ec7811115d4a.

We won't be ready to use newer thrift until proxygen gets updated. :(