MDL-45538 files: restore missing records in draft areas
MDL-47966 Add default content type and encoding
MDL-47903 mod_forum: Add discussion subscription time

This helps us to only send notifications for messages the user should have
already seen.
MDL-47903 mod_forum: Correct test fails related to caching and time

This adds a reset of the discussion and forum cache when running the mail
and maildigest tests.

These test fails were highlighted by the addition of new tests which
add similar post ids.
MDL-26447 gradebook: Default gradedisplaytype fixed for all locales
MDL-47987 mod_forum: Users subscribe to discussions not forums

Correct language string which describes users subscribing to a discussion,
and use it when subscribing on post.
MDL-47864 grade_report: Edulevels according to default user permissions
MDL-47864 tool_monitor: Change edulevels

Considering that the most common use case
to manage rules is an admin CRUDing them.
MDL-45204 phpunit: Fixed test_localcachedir test

make_localcache_directory is the first call to make
localcache, which is already created by reset. So deleting
existing localcache directory will pass this test
MDL-47758 tool_monitor: prevent DB error when revisiting a delete URL
MDL-47758 tool_monitor: altered behat tests so they pass
MDL-48008 gradeimport_xml: report errors usefully
MDL-48010 grade import from URL: don't corrupt the URL.
MDL-47465 tool_monitor: add a new column to subs
MDL-47465 tool_monitor: Ignore used events

An event that has already contributed to a notification should not contribute to another notification for the same subscription.
This needs to be done so we do not overwhelm the user.
Merge branch 'MDL-47465-master' of git://github.com/ankitagarwal/moodle
MDL-47361 tooL_monitor: string and UI changes
Merge branch 'wip_MDL-47966_m28_defaultheaders' of https://github.com/skodak/moodle
MDL-47361 tool_monitor: altered behat tests so they pass
MDL-47983 tool_monitor: Removing only-for-admins restriction