VB case issues
At run-time, build a /Presets path if it doesn't exist

This folder will store all last-used and user-saved presets on a
per-tool basis
New XML support functions

Required for tool preset loading/saving; additions should be
self-explanatory
Many Command Bar user control updates

Last-used settings are now saved and restored.  I still need to write
hooking functions that tool dialogs can use to add custom data (custom
interfaces like Curves and Perspective will need this), but all standard
controls are loaded and saved correctly.

Also began work on user-created presets, but it's only halfway done at
present.  More to come this weekend.
Added allowPreview control to Brightness/Contrast

All tool dialogs will need this ability, as the command bar user control
will change control values during form load, which can trigger a bunch
of preview updates and make the dialog take awhile to appear.