Fix import check for case sensetive namespaces
If you already have namespace `ABc` and you try to import project with namespace `abC` - import will fail with 422 error.
cc @valery
See merge request !1618
Correctly set default projects limit for new users.
See #2014.
Note that the projects limit still isn't retroactively applied to existing users (probably as intended)
See merge request !1547
Fix note attachments XSS and access control
Replaces the reverted #1528, as proposed in https://gitlab.com/gitlab-org/omnibus-gitlab/issues/434, as discussed with @dzaporozhets and as summarized in #2032.
@marin Could you take a look at the nginx config and apply it to Omnibus once this gets merged?
See merge request !1553
Fix duplicate authorized applications
On the profile applications page, display one row per authorized app instead of one row per access token. See #1987.
cc @sytse
See merge request !1524
Add links to the quick help list
Add links in the quick help list to the pricing and feature comparison pages on about.gitlab.com. See #1969
cc @sytse
See merge request !1525
Allow users that signed up via OAuth to set their password in order to use Git over HTTP(S)
See #1982.

There's a similar tooltip for SSH: "Add an SSH key to your profile to pull or push via SSH". These are always shown on-hover, even if the persistent flash above was hidden.
cc @sytse
See merge request !1512
Prevent autogenerated OAuth username to clash with existing namespace.
If the OAuth username already exists as a group rather than a user, automatic account creation would still fail.
See merge request !1511
Test settings for issue tracker service
This adds minimum logging and response when using "test settings" button when the service is enabled.
See merge request !1506
Add tracker integration doc and help page on service
Added documentation on how to enable tracker integration. Fix the active link on the admin page. Added help under the JIRA service page.
See merge request !1508
Add headings to signin/signup blocks on signin page.
See #1986

When signup is disabled, the heading for sign in only reads "Sign in", because there is no longer a choice of Existing/New user.
I've moved the OAuth signin options to just below the signin box because it looked odd as a separate box without a heading.
cc @sytse
See merge request !1516