docs(all): fixes typos and improves readability
fix(views): respect icon_sizes config values when rendering icons

Remove hard-coded references to available icons sizes and use global icon_sizes config values and keys instead
Merge pull request #7088 from hypeJunction/icon-sizes

fix(views): respect icon_sizes config values when rendering icons
docs(cron): adds RST documentation about cron jobs

Converts wiki cron page to RST and references cron in Upgrading docs

Refs #6884
docs(all): improves formatting and comprehensibility of docs

Reworded some paragraphs to make more sense to new users. Applied formatting to some lists and paragraphs
Merge pull request #7087 from hypeJunction/docs

Fixes typos and adds cron RST docs
fix(embed): Manually load CSS/JS libs for embed when editing comments on the activity page.

Fixes #6422
Merge pull request #7107 from brettp/embed_activity_ajax

fix(embed): Manually load CSS/JS libs for embed when editing comments on...
fix(embed): Checking for lightbox and embed before loading JS libs when requested through AJAX.

Refs #7107.
feature(discussion): Added some extension points at discussion sidebars.
These changes allow 3rd party plugins to extend discussion sidebar, and add
there features like a subscribe to discussion button, a list of most popular
posts or most active users...
chore(composer): Use composer to load mrclay/minify

BREAKING CHANGE:
The CSSMin class included via minify was renamed to CSSmin.
If you were referring to it with capital M, you'll have to
change that to lower-case m.

However, note that Elgg's dependencies are not considered
public API, so this notice is only a courtesy. Please explicitly
declare your dependencies on third party vendors, even ones that
you know Elgg already includes. We may remove or update them at any time.
fix(walled_garden): ACCESS_PUBLIC no longer available in group context

When walled garden is enabled ACCESS_PUBLIC is removed from the access
options, except in the group context. This fix also removes it for the
group context.
fix(groups): removes ACCESS_PUBLIC from visibility options if walled
garden is enabled

In a walled garden site nothing is allowed to be public, this also
applies to the visibility of groups
Merge pull request #7038 from jeabakker/group-visibility-walled-garden

fix(groups): removes ACCESS_PUBLIC from visibility options if walled garden is enabled
Merge pull request #7035 from jeabakker/groups-walled-garden

fix(walled_garden): ACCESS_PUBLIC no longer available in group context
chore(tests): Add engine/classes as target for PHPUnit tests

This allows you to temporarily move the test file next to its source file
when you are actively developing and testing with it so that it's easier
to switch between two (which happens frequently in TDD).

The test should still be moved back to engine/tests/phpunit when committed.

Refs #7112
chore(install): Move installer classes to classes dir

This allows the classes to be autoloaded just like all the others.

Fixes #7111
Merge pull request #7110 from sembrestels/discussion-sidebar3

feature(discussion): Added some extension points at discussion sidebars.
Merge pull request #7122 from ewinslow/phpunit-src

chore(tests): Add engine/classes as target for PHPUnit tests
Merge pull request #7079 from ewinslow/composer-minify

chore(composer): Use composer to load mrclay/minify