Updates project to process web hooks async via sidekiq.

A new queue of "project_web_hook" is used to process web hooks asynchronously, allowing each to succeed/fail (and be retried) independently.

(Basically, project web hooks now process the same as system hooks.)
Merge pull request #2784 from AlexDenisov/gitlab_check_environment

Missing environment added to 'Try fixing it' block
Add projects page to dashboard. Remove projects pagination on dashboard
Dashboard to resource
Make group name a link at header
Fixed dashboard show specs
Fix features
feature tests
Merge pull request #2787 from gitlabhq/features/projects_page

Feature: Projects page
Pager.js to coffee
Merge pull request #2768 from rlaneve/feature/queued-web-hooks

Updates web hooks to process via queue
Add deploy.html for symlink if maintaince
Multiple ways for gitlab startup
Added note and link for possible export formats