Refactor PasteScript to be minimalistically included inside templer.

First try, very ugly code with broken tests :-)
cleanup
remove Paste from setup.py
avoid running egg_info
make control script relay the 'add' command to templer.localcommands
Added a "--force" command-line option; added information about local commands to the help message; added a warning that gets displayed when templer is run inside a distribution itself originally created by templer, and that does not have any local commands; added a allowed_packages attribute that gets set to 'global', 'local', 'all' or 'none', depending on where templer is run; added available local commands and templates to the listings.
whack all the stuff related to svn adding
let us use templer in tests instead of paster
Merge branch 'davisagli-local-commands'

Conflicts:
	CHANGES.txt
	CONTRIBUTORS.txt
	src/templer/core/control_script.py
	src/templer/core/tests/test_script.py

resolve conflicts in script exit by preserving the changes to raise errors rather than mask them