Added GitHubApiUrl and GitHubDomain to settings and template
Put values from settings into handler/auth.go
Use custom github domain for webhook
Update all github clients in code
Added settings to github_add page (fix redirect)
Fixed identation
Make IsGit check less strict
Fixed another github client instance in code
Merge commit '7e89478b8b0368d771e44337edc99ab3f527e5f2'