Applied Labels being vertically aligned to the top when next to a Table in the GTK+ backend.
Split out the default definitions of Control.allocate() into a single place.
Added preferred size tests to zz_test.go; these will help for what we're about to do (implement Control.preferredSize() on all other platforms).
Disambiguated what happens when a regular Label is used in a Standalone context.
Resolved a TODO about label alignment.
Applied non-standalone Label offsets to the Windows backend. Also more TODOs.
Changed LPCWSTR to LPWSTR in the Windows code as the C means const and there are a few cases of const->non-const conversions as a result.
Fixed up more LPCWSTR->LPWSTR conversion, including some code simplification.
Added a function to the Windows backend to keep track of text length. This will be important for sizing purposes.
More Windows sizing framework code: merged together the MulDiv() instances into wrapper functions and added the basic text length storage into controlbase.
Converted direct usages of C.setWindowText() in the Windows Control code into calls to the equivalent Control methods so the text length can be properly stored.
Implemented preferredSize() for Label on Windows. Seems to work...
More TODOs.
Removed previous commit's TODO and added Checkbox preferredSize() on Windows.
Added TextField preferredSize() on Windows.
Added Table.preferredSize() on Windows.
Implemented Button.preferredSize() on Windows.
Added debug chatter to Button.preferredSize() on Windows.
Cleaned up sizing_windows.go now that the important things have been reimplemented.