Pass list of changed files in a temp file.

Summary: There is a limit on how long command line invocations can be,
and a long list of files can easily exceed that limit.

Also remove the string truncation logic as we will no longer be
overflowing the screen with a single command.

Reviewed By: @​svcscm

Differential Revision: D1697045
fix broken scuba logging

Summary: Return back to ClientBuild when we're successful so we log CLIENT_BUILD_FINISH.
This isn't a disaster since we still have basically the same data spread out
in scuba table hh_build_steps, but might as well fix this.

Reviewed By: @paulcavallaro

Differential Revision: D1694667

Signature: t1:1694667:1416516191:54be6b1c677a9316acfcbad123e8672a6ea8b35b
point doc blocks for builtins to docs.hhvm.com

Summary: ... instead of php.net. This is quite useful for features
 that exist only in HHVM and not PHP5 (such as hack collections).

 Facebook: HipHopSpecific is really quite a misnomer at this point, as
 it seems to be applied only to stuff that isn't documented because
 it's not yet open sourced (and rather rarely internal to the VM).

Reviewed By: @JoelMarcey

Differential Revision: D1693767

Signature: t1:1693767:1416532376:acf87a1bf5dd361a1d1f9cfaa915c32823b973f4
Make BigNode parsable, extend HeapIter to visit BigNodes.

Summary: Now, clients of HeapIter will visit everything in the heap,
not just objects in slabs. Using the standard format isn't
strictly necessary for iterating, but it enables the HeapIter
client to inspect a standard header, to see it's kind.

Reviewed By: @jdelong

Differential Revision: D1687825
Dump typedef info in `hh_client --show`

Summary: Occasionally useful.

Reviewed By: @int3, @elgenie

Differential Revision: D1695998

Signature: t1:1695998:1416530544:befee9d06783c4130d824db3191905f7a20587f7
Cleanup of hfsort

Summary: I want to embed the core of hfsort into hhvm to use for perf based
jit relocation, so move it into its own namespace, and move error() and TRACE
out of the core so they can be replaced with something more appropriate when
running from hhvm.

Reviewed By: @ottoni

Differential Revision: D1697874

Signature: t1:1697874:1416607428:0c68d05310bd047b6bf7d9db4be8dceeb5dbaaab
Fix headerTest

Summary: It was written to the old api

Reviewed By: @alexmalyshev

Differential Revision: D1698880

Signature: t1:1698880:1416617532:3111a9d67b0624be5cbfccbea7bf019a192028e2
typechecker: add constants to hh_client --show

Summary: ... it's valuable for checking whether a builtin constant is declared.

Reviewed By: @jwatzman

Differential Revision: D1696607

Signature: t1:1696607:1416616316:bb07a63e2dd07da4ac39014ea8fbc0252ecba5b0