remove holland.core.dispatch - no longer used
remove holland.core.hooks

This interface has been replaced by holland.core.backup.hooks
update CHANGES.txt for holland 2.0.0
cleanup holland/__init__.py

- flesh out docstring
- remove old __version__ information
update holland.version

- add __version_info__ a tuple of the __version__ string
- add docstring
update scripts/version_bump to handle holland.version
update holland version in documentation
update holland.spec for 2.0.0