Default setlocale(LC_CTYPE, ""); on startup.

Summary: To match PHP5 default behavior.

Note that you shouldn't rely on default behavior.
Set your locale explicitly.

Closes #3011

Reviewed By: @paulbiss

Differential Revision: D1660528

Signature: t1:1660528:1415175877:b4f11df38d40bdae87f8cd50a09a9ec62da60ba2
Fix IDL style const declarations to use int64_t, not long

Summary: long *may* be symnonymous with int64_t, but it might not be.

Closes #3551

Reviewed By: @paulbiss

Differential Revision: D1660464

Signature: t1:1660464:1415168294:e2d2a87eb3e25fc0f045bc9ba33fbe37a0aef12c
Add regression test for PDO::ATTR_ERRMODE with invalid value

Summary: http://github.com/facebook/hhvm/issues/2307 reported this as broken
but it's working now.  Add a unit test to make sure it never breaks again.

Closes #2307

Reviewed By: @paulbiss

Differential Revision: D1660479

Signature: t1:1660479:1415168323:19f05338bde37cbff5d2adb7418fdcffeb2808b1