Adds warnings for uncallable handlers in hooks/events.
Adds units for the warnings.
Injects logger into events/hooks services.
Ensures logger, events, and hooks are setup in right order in service provider.
Fixes small bug in DI container.
Fixes #6300: Deprecated $CONFIG still available in view scripts
More CHANGES.txt and RST updates
Merge pull request #6344 from mrclay/docs

More CHANGES.txt and RST updates
feature(views) Eases extending the input/view view

In order to extend forms *outside* the form element, devs must extend the 
input/form view, however it's a bit cumbersome to determine the current
action because you have to extract it from the "action", which is a URL. This
gives the extending view the raw action name.

Fixes #6129
Merge pull request #6335 from mrclay/6300

Fixes #6300: Deprecated $CONFIG still available in view scripts
fix(memcache): Better logging of save/hits/misses

Fixes #6243
Merge pull request #6347 from mrclay/6243

Better logging of save/hits/misses
security(http): Adds anti-clickjacking header when serving pages

Adds a header that prevents framing pages from different domains in
modern browsers. A plugin hook allows disabling/altering the headers
sent.

Fixes #6098
docs(events): Reword docs for hooks

Puts the location of the triggering of the hook before what it filters
feature(search): Allows filtering/reordering types returned in search

This adds a trigger hook to allow filtering/reordering the types and
subtypes queried and displayed.

Fixes #6118
fix(plugins): Stops junk log entries created on plugins page

If a plugin's directory was removed, viewing the plugins page results
in this plugin being re-disabled again and again, adding junk log
entries. Now we only disable if the plugin wasn't already disabled.

Fixes #6066
Merge pull request #6351 from mrclay/6066

fix(plugins): Stops junk log entries created on plugins page

If a plugin's directory was removed, viewing the plugins page results
in this plugin being re-disabled again and again, adding junk log
entries. Now we only disable if the plugin wasn't already disabled.
Merge pull request #6350 from mrclay/6118

feature(search): Allows filtering/reordering types returned in search
Merge pull request #6349 from mrclay/docs_hook_reorder

docs(events): Reword docs for hooks
fix(embed): make tabs in colorbox popup usable

Function embed_select_tab expects input page to be set, but it isn't.
Adding a
´´´
set_input('page', $page[1]);
´´´
to the embed_page_handler function fixes this

Refs: Issue #6357
fix(embed): make pagination in embed colorbox usable

View mod/embed/views/default/embed/list.php is missing a base_url for navigation.

Adding 'base_url' => elgg_get_site_url() . "embed/" to the options for pagination fixes this

Refs: Issue #6357
Merge pull request #6265 from mrclay/uncallable_handlers

Adds warnings for uncallable handlers in hooks/events.
Merge pull request #6348 from mrclay/6129

Eases extending the input/view view
docs(hooks): Corrects docs syntax error