fix new relic team promo UI

- un-hide the promo copy
- show the entire promo t-shirt image
- align promo copy and image
- move call to action to the right side of the copy
Merge pull request #257 from codebender/fix/new_relic_promo_ui

fix New Relic team promo UI problems - Bounty #440
disable registration submit button after 1 click
Merge pull request #259 from codebender/stop_double_clicks_at_registration

disable registration submit button after 1 click
Fix User#on_team?
fix TeamsController#show
clean up Team model duplication and fix grouping

- Remove duplicate association declarations
- Remove duplicate method declarations
- Remove duplicate mount_uploader
- Remove duplicate callbacks
- Remove duplicate validations
- Group associations
- Group callbacks
- Group validations
Merge pull request #261 from jakegavin/welcome-email-bug

Bounty #455 - Fix User#on_team?
Merge pull request #262 from codebender/team_model_cleanup

clean up Team model duplication and fix grouping - Bounty 462
Merge pull request #263 from jakegavin/fix-missing-opportunity

Bounty #459 - Fix
destroy zombie likes when likable is invalid

 - or when a Like tracking code doesn’t associate to a user
Merge pull request #260 from codebender/bad_likes

destroy zombie likes when likable is invalid - Bounty 456
Remove blog from coderwall
Merge pull request #266 from lblackburn/master

Remove blog from coderwall
remove leaderboard
Merge pull request #267 from seuros/master

remove leaderboard