Bug 741125: Update WebIDL parser.

client.py

dom/bindings/parser/WebIDL.py

dom/bindings/parser/__init__.py

dom/bindings/parser/runtests.py

dom/bindings/parser/tests/test_array_of_interface.py

dom/bindings/parser/tests/test_builtin_filename.py

dom/bindings/parser/tests/test_constructor.py

dom/bindings/parser/tests/test_deduplicate.py

dom/bindings/parser/tests/test_enum.py

dom/bindings/parser/tests/test_error_colno.py

dom/bindings/parser/tests/test_nullable_equivalency.py