Fix group matching SQL query

The check there is intended for the :members_mods_and_admins level, which is not automatically checked for normal users. Instead, the :everyone level is the one used, which would always fulfill the "alias_level in :levels" check.

This changes the :everyone level to :members_mods_and_admins, which was originally intended.
Change to case-insensitive matching in group @name matching
Adds unit tests for SearchController
Adds new QUnit assertion ("not") complementary to built-in "ok"
FEATURE: add a 14 days window to consider topics new
Updated with tips for Postgres93.app

It took me a while to figure this out, so hopefully it helps someone use discourse in the future.
Update the OS X development documentation

* Remove some outdated information from the guide
* Add scripts/osx_dev to bootstrap a working development environment
* Add a Brewfile to track binary dependencies
Add site setting for category of topics created by embedding
copyediting on topnav tooltips
/top tooltip clarification
omit needless words
BUGFIX: PMs could be created with a category

BUGFIX: hide category column when displaying the list of private messages
Merge pull request #1857 from velesin/qunit_not_assertion

Adds new QUnit assertion ("not") complementary to built-in "ok"
Merge pull request #1856 from velesin/search_controller_tests

Adds unit tests for SearchController
Allow using the API when Login required site setting is on.
Merge pull request #1861 from slainer68/login_required_allow_api

Allow to use the API when Login required site setting is on
BUGFIX: view latest topics should point to /latest and not /
BUGFIX: taller keyboard shortcuts modal to prevent then scrollbar
Merge pull request #1860 from ecuk/embed-category

Add site setting for category of topics created by embedding
Merge pull request #1859 from nragaz/mac-os-x-setup

Update the OS X development documentation