Merge branch 'improve_jira_integration_doc' into 'master'

Improve jira integration doc for new version

See merge request !308

doc/integration/jira.md

 # GitLab JIRA integration
 
-GitLab can be configured to interact with JIRA
-
-*Note* Directions below are for JIRA v6.x and GitLab v6.x
+GitLab can be configured to interact with JIRA.
 
 ## Configuring JIRA
 
 We need to create a user in JIRA which will have access to all projects that need to integrate with GitLab.
-Login to your JIRA instance as admin and under Administration -> User Management create a new user.
-For example, let's create user `gitlab`. We've also added `gitlab` user to group `jira-developers` which grants it access to projects.
+Login to your JIRA instance as admin and under Administration go to User Management and create a new user.
+As an example, we'll create a user named `gitlab` and add it to `jira-developers` group.
+
+**It is important that the user `gitlab` has write-access to projects in JIRA**
 
 ## Configuring GitLab
 
+### GitLab 7.8 EE and up with JIRA v6.x
+
+To enable JIRA integration in a project, navigate to the project Settings page and go to Services. Here you will find JIRA.
+
+Fill in the required details on the page:
+
+![Jira service page](jira_service_page.png)
+
+* `description` A name for the issue tracker (to differentiate between instances, for instance).
+* `project url` The URL to the JIRA project which is being linked to this GitLab project.
+* `issues url` The URL to the JIRA project issues overview for the project that is linked to this GitLab project.
+* `new issue url` This is the URL to create a new issue in JIRA for the project linked to this GitLab project.
+* `username` The username of the user created in [configuring JIRA step](#configuring-jira).
+* `password` The password of the user created in [configuring JIRA step](#configuring-jira).
+* `api version` The version of the JIRA API. By default, version `2` is used.
+* `Jira issue transition` This is the id of a transition that moves issues to a closed state. You can find this number under [JIRA workflow administration](jira_workflow_screenshot.png).  By default, this id is `2`. (In the example image, this is `2` as well)
+
+After saving the configuration, your GitLab project will be able to interact with the linked JIRA project.
+
+This will allow users to mention JIRA issues in comments in merge requests and comments on commits by mentioning the issue as such:
+`PROJECT-5`.
+
+You can close JIRA issues by writing `Resolves PROJECT-5` or `Closes PROJECT-5` in commits and merge requests. After pushing the commit or merging the merge request, the referenced JIRA issue will be automatically closed.
+
+![example of mentioning or closing the JIRA issue](jira_issue.png)
+
+
+### GitLab 6.x-7.7 with JIRA v6.x
+
 In `gitlab.yml` enable [JIRA issue tracker section by uncommenting the lines](https://gitlab.com/subscribers/gitlab-ee/blob/6-8-stable-ee/config/gitlab.yml.example#L111-115).
 This will make sure that all issues within GitLab are pointing to the JIRA issue tracker.