Dump: Move QUnit.jsDump to QUnit.dump

Fixes gh-592
Ref gh-591
Build: Move jsdiff to external directory

Closes gh-591
Assert: Assert is now an instanced object exclusive to test blocks
Push: Push and PushFailure are now assert.custom and assert.failure
Test Obj: Using exaclty context instead of config.current
Test Obj: pushFailure method is no more a static method