add `version skew` item to project browser

- version skew appears when the git commit associated with the image
  is different than the HEAD of the git repository. The `version
  skew` menu item shows the diffs bewteen the two versions.
project list work (sorting, emphasis, hookup project dirs)

- sort dirty and `active` projects at top of project list
- unloaded projects included in list (at bottom)
- `get` menu item added .. get configuration so you can look at config
- project node in a directory in /home gets extension info included ...
  - node includes projectSpec for loading (if not loaded)
  - list of overridden functions
  - whether or not the project is active
- wire out auto package/config display
poor man's hack for stepping over code that interacts with Transcript

- there is a new option the step gci call that should allow
  stepping over Transcript interactions, however for 3.1 and
  2.x this will fill the bill...
unloaded project entries reveal their target version
checkpoint ... major overhaul of `project list` ... add support for pure git repository management

- the webEditionHome or todeHome git repository needs to be managed from within
  tODE ... generic support for managing any old git repo added in
- refactored the (former) TDAbstractMetacelloRegistrationDefinition renaming it to
  TDAbstractProjectRegistrationDefinition and jiggering hierarchy.
  TDMetacelloRegistrationDefinition survived finding a new place in the hierarchy.
- TDProjectEntryDefinition (formerly TDProjectExtensionsDefinition) class hierarchy
  added to support the on disk project registration node
arrange for doing diff for git-only repo

- history not available in diff browser when doing plain diff
git project improvements

- display dirty mark
- show git repo branch
- MetacelloPlatform method take directory path as arg now
final(?) git project adjustment

- only the metacello registration needs to track the version info
  after a commit