Issue #561 - Execute inline JS.

This follows the approach of external scripts in executing tests all together after parsing finishes.
Fix logic in http_loader

We don't need to repeatedly read the headers, and need to send the Done message.
auto merge of #869 : Ms2ger/servo/inline-script, r=jdm

This follows the approach of external scripts in executing tests all together after parsing finishes.
auto merge of #870 : brson/servo/http, r=metajack

We don't need to repeatedly read the headers, and need to send the Done message.
sub.mk: Remove CFLAGS_mozjs

Seems to have no effect.
Add SpiderMonkey debug build fix
auto merge of #871 : kmcallister/servo/debug-build, r=metajack
Remove unreachable code from http_loader
auto merge of #872 : brson/servo/http, r=metajack

It was a silly mistake.