feature(aalborg_theme): adds visual difference between submit and action buttons

Fixes #6929
perf(views): remove unneeded view calls in river/elements/body view

Since item summaries are commonly set, we now only render the default
summary view when the summary is really missing. This also reduces the
number of NOTICEs about missing translation keys.
feature(router): add original params to route hook

fixes #7284
feature(plugins): added default param to elgg_get_plugin_user_setting

fixes #7260
feature(views): output readable access level for any access_id

Do not require an entity to display a human readable representation of an access_id

Fixes #7133
feature(filestore): add a hook to fix detected mimetype

Moves mimetype detection logic for Microsoft zipped formats from a file
plugin into a core plugin hook.
Adds missing reference to mime_type,file hook in the list of
available hooks.
Adds information about available hooks for filtering mime and simple types
to upgrading instructions. Informs plugin devs that Microsoft
zipped format detection snippet can be removed from file upload actions.
feature(site_notifications): option to mass delete site notifications …

When a user has a lot of site notifications he/she has to delete them
individually. This is very time consuming, so this solves that problem

fixes #6219
feature(filestore): add elgg_get_file_simple_type() to core api

Consolidate simpletype parsing logic in a new elgg_get_file_simple_type() function added to core api
chore(docs): document simple_type,file hook
deprecate(filestore): deprecate file_get_simple_type() and file_get_general_file_type()

Deprecate file_get_simple_type(), found in mod/file/start.php, and file_get_general_file_type(), found in engine/lib/filestore.php in favour of a pluggable elgg_get_file_simple_type() added to core api