Gem cleanup.

* Update gemspec to use latest best practice.
* Add a version.rb file
* Update 'requires' to use relative paths.
Merge branch 'scottjacobsen-gem-cleanup' into stage
Fix version constant
Fix requires in Rack startup
Upgrade Unicorn
Support for adding (the wrong) CMore logo

in the wrong size, to the top right corner.
New CMore logo, in top right corner
Making logos configurable (sort of)
Merge branch 'stage'