Allow fully-yanked gems to be unyanked by the original owner

This still allows for a new user to swoop in and claim the gem by pushing their own version. Doing so would delete the previous ownership.
Refactor to yank a version directly rather than through its gem
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
Add Badge link to Rubygem pages
Merge branch 'master' of git://github.com/rubygems/rubygems.org
Add test for badge_link helper
Merge branch 'master' of git://github.com/rubygems/rubygems.org
Remove unnecessary group by all columns

Signed-off-by: João Soares <jsoaresgeral@gmail.com>
Redirect searches with a single exact match.

When a search results in only a single exact match, redirect to the gem
page instead of showing the search results.
Update launchy dependency to version 2.3.0
Use rubygems 1.8.25
Don't bother testing against Ruby 2.0.0
Fetch only the needed field in reverse dependency query
Drop long output version of reverse_dependencies api call