Implement all GObject-introspection test suites

Basically this changes testGIMarshalling.js and testEverything{Basic,Encapsulated}.js to implement all of the tests from the GObject-introspection test suites, so that we get the maximum coverage out of them. It also reorders and moves tests as needed so that we have three test scripts (testGIMarshalling, testRegress, testWarnLib) that correspond one to one with the C test files from GObject-introspection, and all tests are in the same order so that it's easy to see if one is included or not.

Any tests that don't work are marked "pending" with a bug link attached.