Simplify HTMLCollection predicates
Fill out various proxy binding traps as part of making setters work. Add named getter and setter and indexed getter support, as well as proxy object expandos. Fixes #660.
Implement clear
Update submodules
Place float children of floats correctly in the flow tree.
Fix the handling of flow_contexts in floats.

The num_floats was hard-coded to 1 and didn't take into account the
children. Also the float context was not being threaded through the children
properly.
Move webidl files to dom/webidl
Modify BindingGen.py(add outputFolder)
Update Makefile.in(for BindingGen.py)
Update Makefile.in(add bindings-test)