Reimplemented CompoundPathFilter in C++.
Dealing with dict->CompoundData user data in PathFilterWidget.
Reimplemented GafferScene.ScenePath in C++.
FileSystemPath in C++. WIP - needs filters in C++ and attribute queries.
FileSystemPathBinding fix.
Reimplemented FileNamePathFilter in C++.
Half-done FileSystemPath::createStandardFilter()

Need new filter features to do the rest.
Fix for python object identity problem.
Fixed object identity test for FileSystemPathFilter C++
Fixed FileNamePathFilter to not show hidden files by default.
Reimplemented LeafPathFilter in C++.