Allow typechecker to interpret WaitHandle result()

Summary: Avoid problems with typechecker on hhvm 3.5 version
Closes https://github.com/facebook/hhvm/pull/4405

Reviewed By: @jano

Differential Revision: D1724448

Signature: t1:1724448:1418076102:74b9fc566f8720d1493d19b568f47b98448866a2
Fix use-after-free in soap extension

Summary: Binding a StrNR to a const String& results in a dangling
reference.

Reviewed By: @swtaarrs

Differential Revision: D1725840

Signature: t1:1725840:1418075846:75cf7115c6fb2c48b81023cb9dd5bf4a1d2ff9f7