add stack overflow to help page

details on looking for correct installation guide

added stack overflow as support option

no need to download init and nginx files since they are in repo now

Fixed typo in CHANGELOG.md

styling and typo fixes in installation guide

addresses gitlabhq/gitlabhq#3809

Hipchat service implementation

improve regrex for match(sidekiq) robustness

Fixed typo in Readme.md

Security: keep the Rails secret token out of version control.

Store the secret token in a .gitignored file called ".secret", which is
created by the initializer if it doesn't exist.

Fixed 22th -> 22nd