Add settings for user permission defaults

“Can create groups” and “Can create teams” had hardcoded defaults to
`true`. Sometimes it is desirable to prohibit these for newly created
users by default.
Give examples that have been reported frequently.
GitLab must run before the check is done.
Fix link 404.
Use default cursor on network graph.

The cross 'move' cursor doesen't work if you can't it around.
refs #3741
[FEATURE] Basic user_teams api

 * Closing #3066
 * Closing #3609
Include groups in import with import repos rake task

Expand the import glob to include `**/*.git` to find projects in groups
as well as top level projects.  Check for existing group, and create
group if needed.  Set namespace_id for imported projects.
Fix regression caused by using newer version of Grape

This commit fixes the regression caused by using a newer version of Grape and Grape entity.  This solves Issue 4023.
details on looking for correct installation guide

addresses gitlabhq/gitlabhq#3809
Fixed typo in CHANGELOG.md
styling and typo fixes in installation guide
no need to download init and nginx files since they are in repo now
Merge pull request #4081 from bbodenmiller/patch-9

styling and typo fixes in installation guide
Merge pull request #4080 from babatakao/patch-1

Fixed typo in CHANGELOG.md
Merge pull request #4082 from bbodenmiller/patch-10

no need to download init and nginx files since they are in repo now
remove branch dependencies where not necessary
clarify when issue tracker is to be used so as to not contradict issue tracker guidelines and maintenance policy
added stackoverflow as support option
Merge pull request #4089 from bbodenmiller/master

added stack overflow as support option
add stack overflow to help page