* add note to Events API
* add author section to Events API
* add noteable_id and noteable_type to Notes API

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

UI: Sidebar & header tweaks and fixes

Depends on !1953 

See the commits for more details, the messages mostly speak for themselves.

![Logo](https://gitlab.com/gitlab-org/gitlab-ce/uploads/ba088150165bb0a0aea1e894f3443f43/logo_tooltip.png)

![Sidebar](https://gitlab.com/gitlab-org/gitlab-ce/uploads/c1e8c09ac3bf489cdb9531eebea18c90/sidebar_tooltips.png)

Fixes #2928, #2071, https://dev.gitlab.org/gitlab/gitlabhq/issues/2575, and https://dev.gitlab.org/gitlab/gitlabhq/issues/2573

See merge request !1958

UI: Improve form consistency

Depends on !1953

See the commits for more details, the messages mostly speak for themselves.

# Highlights

## Tag form

Before:

![tag_before](/uploads/ee5ba6ef405749013f9e5717ebcf72f3/tag_before.png)

After:

![tag_after](/uploads/71bb543553190d91c03fd706cce35923/tag_after.png)


See merge request !1955

Fix background and padding of login and error pages

Was gray, is white again.

See merge request !1978

Correction of markdown in SSH docs

Correction of broken markdown in SSH docs

See merge request !1900

Don't show project fork event as imported

See merge request !1949

Add authorization to new branch/tag pages.

The create actions have authorization, the new actions didn't,
so no-one unauthorized could actually do anything, but it was wrong(TM).

See merge request !1979

Update .ruby-version to 2.1.7

Fixes #3835

See merge request !1980

fixes #3263 slashes are replaced with two underscores



See merge request !1981