Add support to HHBBC for marking all functions interceptable

Summary: Will be turned on when you set the compile-time option to enable
rename function.  At repo build time, will add AttrInterceptable to every
function, so you don't need to specify EnableRenameFunction at run time.

Reviewed By: @markw65

Differential Revision: D1434019
Clean up CONTRIBUTING.md

Summary: CONTRIBUTING.md was mostly a duplicate of a section in README.md. I
deduped the content, cutting the README.md section down to a link to
CONTRIBUTING.md. I also reordered and cleaned up some of the text in
CONTRIBUTING.md.

Closes #3205
Created from: https://github.com/facebook/hhvm/pull/3205

Reviewed By: @ptarjan

Differential Revision: D1439724
bump third-party submodule hash
Merge pull request #3208 from dcsommer/master

bump third-party submodule hash
Add quick jit to framework test runner

Summary: Todo in separate diffs:
 - investigate why FB build has some test failures when run this way, but OSS doesn't (same for quickinterp)

Reviewed By: @LiraNuna

Differential Revision: D1438880
Move ti/proxygen/lib to proxygen/lib

Summary: As in title. This is where proxygen lives now.

Reviewed By: praveenr

Differential Revision: D1439906
Add intra-trans arcs when building wholecfg region

Summary: When I wrote the wholecfg selector I missed the fact that the "input"
regions can have internal arcs -- for instance, when inlining has happened.
Bringing these arcs in solves some weird problems that were popping up in the
repo-mode unit tests.

Reviewed By: @ottoni

Differential Revision: D1439318