Patch existing find_or_initialize_version_from_spec to make size an optional parameter.
size_in_kilobytes -> number_to_human_size
Change to cleaner syntax.
Add size to versions.
brought Chris's patch up to date and added a script to calculate sizes for existing gems
cleaned up Version#size interface
smoothed out size interfaces in Pusher and Rubygem
Merge remote-tracking branch 'gnarg/master' into size

Conflicts:
	app/models/pusher.rb
	db/schema.rb
	features/push.feature
	test/unit/pusher_test.rb
Revert "Remove unnecessary group by all columns"

This reverts commit b7dd57be0332acd088b2b95a13ca32a69302aec1.
Sort out some failing tests and gaps in tests
Disable unstable test