* Add units concept for modulable functions of a repository

* remove unused comment codes & fix lints and tests

* remove unused comment codes

* use struct config instead of map

* fix lint

* rm wrong files

* fix tests

* Added rel="noopener" to target="_blank" hrefs

* Replaced gogs.io/docs with docs.gitea.io

RepoLink -> Link, RepoRelLink -> RelLink, FullRepoLink -> FullLink

This commit improves templates readability, since all of them use consistent
indent with all template command blocks indented too.

1. Indents both HTML containers such as <div>, <p> and Go HTML template blocks
   such as {{if}} {{with}}

2. Cleans all trailing white-space

3. Adds trailing last line-break to each file

Merges repo/sidebar.tmpl with repo/header.tmpl and makes every repo page use
middleware.RepoRef() necessary to display information on this menu.

This is more inline with way GitHub looks like and feels much more natural and
in style with rest of the interface.

The boolean flags in the repo context have been replaced with mode and two methods

Also, the permissions have been brought more in line with https://help.github.com/articles/permission-levels-for-an-organization-repository/ , Admin Team members are able to change settings of their repositories.