Make sure issue assignee is properly reset.

Previously, when the assignee was reset via the sidebar or bulk edit, `assignee_id` was set to `-1` rather than `null`, which caused the two issues shown below:

![Screen_Shot_2015-03-24_at_16.52.13](https://gitlab.com/gitlab-org/gitlab-ce/uploads/3c937795c45031c3c72c124ced866598/Screen_Shot_2015-03-24_at_16.52.13.png)

- A "(deleted)" participant
- An empty selectbox in the sidebar, instead of "Select assignee"

See merge request !443

Remove duplicate CHANGELOG items for v7.8.0

[ci skip]

See merge request !447

Fix nested task lists

When nesting task list items, the parent item is wrapped in a `<p>` tag.  Update the task list parser to handle these paragraph wrappers.

cc @sytse

See merge request !413

[ci skip]

Don't mark merge request as updated when merge status relative to target branch changes.

Addresses https://gitlab.com/gitlab-org/gitlab-ce/issues/1254 and private issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2165.

See merge request !431

Don't include system notes in issue/MR comment count.

Addresses private issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2163.

See merge request !430

Fix file mode going to next line in diff header

See merge request !432

Don't use required keyword arguments to maintain support for Ruby 2.0.

See merge request !433

This reverts commit af522ede.

Change comment in blue ui to match other scss

Change comment in blue ui to match other scss files

Send EmailsOnPush email when branch or tag is created or deleted.

Addresses #1951, #1957 and #1925.

![Screen_Shot_2015-03-17_at_13.58.15](https://dev.gitlab.org/gitlab/gitlabhq/uploads/16ff25adb4b4a7e1923612e0652442b4/Screen_Shot_2015-03-17_at_13.58.15.png)

![Screen_Shot_2015-03-17_at_13.58.22](https://dev.gitlab.org/gitlab/gitlabhq/uploads/e346c1d84aba3a093b722d0a4167e289/Screen_Shot_2015-03-17_at_13.58.22.png)

![Screen_Shot_2015-03-17_at_13.58.28](https://dev.gitlab.org/gitlab/gitlabhq/uploads/720437ecc13f317c6d20eff82ac60bd7/Screen_Shot_2015-03-17_at_13.58.28.png)

![Screen_Shot_2015-03-17_at_13.58.34](https://dev.gitlab.org/gitlab/gitlabhq/uploads/2b302bb6cdbe27c96a8dff1375236602/Screen_Shot_2015-03-17_at_13.58.34.png)

See merge request !1709

Don't show commit comment button when user is not signed in.

Address private issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2167.

See merge request !429

Conflicts:
	app/controllers/users_controller.rb

Replace commits calendar with contributions calendar

* count opening of issues and merge requests
* dont trigger git repository - use events from database
* count pushes instead of commits for faster and easier counting
* much-much faster since does not affected by repository size

See merge request !420

Fix #8966 Remove Milestones/Labels from project navbar when Issues disabled

Update views to single form of address. Change "my" to "your"

Part of user experience. Every software (twitter, facebook etc) talks to you like "change your password" but not "change my password".

cc @sytse @job

See merge request !1736

Include missing events and fix save functionality in admin service template settings form

### What does this MR do?

This MR includes missing settings left out in the Admin -> Service Templates page and fixes the inability to save certain settings.

### Are there points in the code the reviewer needs to double check?

No.

### Why was this MR needed?

Because the service template form was broken and untested.

### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?

#1275

Before:

![Screen_Shot_2015-03-23_at_5.53.19_AM](https://gitlab.com/stanhu/gitlab-ce/uploads/e1bff75f30a3b6ecb174d3e25c722b7e/Screen_Shot_2015-03-23_at_5.53.19_AM.png)

After:

![Screen_Shot_2015-03-23_at_5.53.13_AM](https://gitlab.com/stanhu/gitlab-ce/uploads/8fada00128a3d0951b3230fefa64be92/Screen_Shot_2015-03-23_at_5.53.13_AM.png)

See merge request !427

Closes #1275

Bump Docker build to GitLab v7.9.0

See merge request !426

Faulty LDAP DN name escaping removed