renamed unused variables properly
Merge remote-tracking branch 'cpradio/keyboard-binding-incoming-updated-topics'

Conflicts:
	config/locales/client.en.yml
Merge branch 'master' of http://github.com/discourse/discourse
FIX: Support J/K bindings on German Keyboards

J/K are not supported on German keyboards, shift+j and shift+k have been added to remedy this.
https://meta.discourse.org/t/keyboard-shortcuts-for-next-previous-section-do-not-work-with-german-keyboard-layout/18902
Change SHIFT+J and SHIFT+K to move up/down sections instead of posts.
Merge branch 'master' of http://github.com/discourse/discourse
FIX: Firefox j/k post navigation is inconsistent
https://meta.discourse.org/t/j-k-navigation-in-lengthy-topics/18945
Merge pull request #2728 from techAPJ/patch-3

UX: add line break before time for post navigator
Merge pull request #2729 from cpradio/firefox-kbd-post-navigation

FIX: j/k navigation for posts using Firefox
add 1GB memory change notes
minor copy updates
minor copy update, Omit Needless Words
FIX: autocomplete username failing to pop up

Janky autocomplete behavior due to debounce not being accounted for
correctly when dealing with promises

This also fixes a promise leak
FIX: Reset changed site settings after import is complete

After an import has finished the site settings should be reset to their
previous values. For example, since 'disable_emails' was set to false
before any import, it wasn't possible to login after the import
(sending email for password reset didn't work).
FEATURE: Badge query validation, preview results, and EXPLAIN

Upon saving a badge or requesting a badge result preview,
BadgeGranter.contract_checks! will examine the provided badge SQL for
some contractual obligations - namely, the returned columns and use of
trigger parameters.

Saving the badge is wrapped in a transaction to make this easier, by
raising ActiveRecord::Rollback on a detected violation.

On the client, a modal view is added for the badge query sample run
results, named admin-badge-preview.
The preview action is moved up to the route.
The save action, on failure, triggers a 'saveError' action (also in the
route).

The preview action gains a new parameter, 'explain', which will give the
output of an EXPLAIN query for the badge sql, which can be used by forum
admins to estimate the cost of their badge queries.
The preview link is replaced by two links, one which omits (false) and
includes (true) the EXPLAIN query.

The Badge.save() method is amended to propogate errors.

Badge::Trigger gets some utility methods for use in the
BadgeGranter.contract_checks! method.

Additionally, extra checks outside of BadgeGranter.contract_checks! are
added in the preview() method, to cover cases of null granted_at
columns.

An uninitialized variable path is removed in the backfill() method.

TODO - it would be nice to be able to get the actual names of all
columns the provided query returns, so we could give more errors
FIX: destroy CategoryGroup when Category or Group is destroyed
Merge pull request #2733 from kamilbielawski/destroy_category_group_when_category_is_destroyed

FIX: destroy CategoryGroup when Category or Group is destroyed
Merge pull request #2732 from gschlager/fix01

FIX: Reset changed site settings after import is complete
FIX: Remove the old keyboard bindings for next/prev section, update client.en.yml to reflect the new bindings
Fix magic numbers, extra param references