Before we have only owner_id to determine group owner
With multiple owners per group we should get rid of owner_id in group.
So from now @group.owner will always be nil but
@group.owners return an actual array of users who can admin this group

* Hooks and team pages allowed only for masters/owners
* Group page allowed for admin
* Corrent authentication for Projects controller
* Hide some project elements from visitor

* Render right layout depends on current_user
* show sample git username/email when repo is empty
* Show extra info when browsing public area
* Fixed some tests related to public projects
* show comments in read-only for public projects
* Remove old public routing

GITLAB-1279 (GITLAB-1264)

Change-Id: Ifb5b4313bc91fae720f8ef5c36152c45e9d38934

-calling build_user will now apply defaults and only override them if as: :admin is set

Change-Id: Id1d938c0967752ecc14370af54f2d88128d18c44

Previously, only number of changed files mattered. Now, number of lines to render in the diff are also taken into account.

A hard limit is set, above which diffs are not rendered and users are not allowed to override that. This prevents high server
resource usage with huge commits.

Related to #1745, #2259

In addition, handle large commits for MergeRequests and Compare controllers.

Also fixes a bug where diffs are loaded twice, if user goes directly to merge_requests/:id/diffs URL.

Show permissions for all project.
Add ability to remove user from group if not an owner
Remove unnecessary admin controller

Provide UI with explanation what happens when you block or remove user
When remove user - remove all groups where user is an only owner

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