Merge branch 'tooltip-change' into 'master'

Update project star/unstar tooltip

## What does this MR do?
Fixes project toggle star button tooltip to show actual tooltip for its state.

## Are there points in the code the reviewer needs to double check?
No.

## Why was this MR needed?
- When you star a project tooltip wasn't changing.
- When you star a project and refresh the page, tooltip was still showing `Star Project`

## What are the relevant issue numbers?
Fixes #18143

## Screenshots (if relevant)

### Before 
![Screen_Shot_2016-06-15_at_15.31.57](/uploads/e005951c23eeed7c2761a0ec1911f3ce/Screen_Shot_2016-06-15_at_15.31.57.png)

### After
![tooltip-change](/uploads/4caec99eac6ffcc7331947fdfdb9e051/tooltip-change.gif)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- [ ] Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4672

CHANGELOG

@@ -93,6 +93,7 @@ v 8.9.0 (unreleased)
   - New custom icons for navigation
   - Horizontally scrolling navigation on project, group, and profile settings pages
   - Hide global side navigation by default
+  - Fix project Star/Unstar project button tooltip
   - Remove tanuki logo from side navigation; center on top nav
   - Include user relationships when retrieving award_emoji
   - Various associations are now eager loaded when parsing issue references to reduce the number of queries executed

app/assets/javascripts/lib/common_utils.js.coffee

 ((w) ->
 
+  window.gl or= {}
+  window.gl.utils or= {}
+
   jQuery.timefor = (time, suffix, expiredLabel) ->
 
     return '' unless time
@@ -21,4 +24,13 @@
 
     return timefor
 
+
+  gl.utils.updateTooltipTitle = ($tooltipEl, newTitle) ->
+
+    $tooltipEl
+      .tooltip 'destroy'
+      .attr    'title', newTitle
+      .tooltip 'fixTitle'
+
+
 ) window

app/assets/javascripts/star.js.coffee

@@ -9,9 +9,11 @@ class @Star
         $this.parent().find('.star-count').text data.star_count
         if isStarred
           $starSpan.removeClass('starred').text 'Star'
+          gl.utils.updateTooltipTitle $this, 'Star project'
           $starIcon.removeClass('fa-star').addClass 'fa-star-o'
         else
           $starSpan.addClass('starred').text 'Unstar'
+          gl.utils.updateTooltipTitle $this, 'Unstar project'
           $starIcon.removeClass('fa-star-o').addClass 'fa-star'
         return
 

app/views/projects/buttons/_star.html.haml

 - if current_user
-  = link_to toggle_star_namespace_project_path(@project.namespace, @project), class: 'btn star-btn toggle-star has-tooltip', method: :post, remote: true, title: "Star project" do
+  = link_to toggle_star_namespace_project_path(@project.namespace, @project), { class: 'btn star-btn toggle-star has-tooltip', method: :post, remote: true, title: current_user.starred?(@project) ? 'Unstar project' : 'Star project' } do
     - if current_user.starred?(@project)
       = icon('star fw')
       %span.starred Unstar