MDL-39563 Fixing mobilecssurl is not being returned in WebService get_siteinfo
MDL-40195: mod_assign: Display grades when quickgrading to 2 decimal places
MDL-40538 caching: Use isset for performance

isset is much faster than array_key_exists. For caches we need to
ensure as much performance as possible. To all null to continue to
be stored and provide correct results, non ttl also now saves in
$this->store[$key][0].  As isset($this->store[$key]) will return
true in all cases.

time() as found in cache::now() can be slow on some platforms and
we shouldn't bother checking it unless needed. It also stops non-ttl
caches paying the ttl price.

Unit tests were adjusted to ensure null is still handled correctly
when we are only using isset.
MDL-40621 fixed small bug in function editor_tinymce_plugin::fix_row()
MDL-39563 Fixing mobilecssurl is not being returned in WebService phpunit tests
MDL-38747 blocks: course format options numsections is required to display the block
MDL-40536 course: unit tests for course_external::import_course

Basic import operations and a specific test case which identifies
a bug.
MDL-40536 course/externallib fix incorrect variable

Fixes test_import_course_invalid_deletecontent_option() from the
previous commit.
MDL-40569 fix empty CSS files after cache purging
MDL-40558 skip admins and guest when deleting incomplete users
MDL-40633 filter_urltolink breaking some image links.

This was a regression caused by MDL-22390. HTML like
<img src="http://www.example.com/logo.gif" />
was being broken.
MDL-40611 fix context cache size expectation
MDL-39062 cache: persist keys now set properly
MDL-39062 cache: version bump to update definitions
Automatically generated installer lang files
Merge branch 'wip-MDL-39062-m24' of git://github.com/samhemelryk/moodle into MOODLE_24_STABLE
Merge branch 'MDL-40633_24' of git://github.com/timhunt/moodle into MOODLE_24_STABLE
Merge branch 'MDL-39563-24' of git://github.com/jleyva/moodle into MOODLE_24_STABLE
MDL-39563: Change to use $CFG consistently
MDL-40585 backup: cache XML parent paths

For $this->groupedpaths, using a key is faster as there is
no need to do in_array searches.

Parent cache allows dirname calls to be substantially reduced.
2048 was chosen as a cache size as this class operates on chunks
of the restore at a time, 8k questions produces a parent cache of
about 500 paths and uses 300K of memory.  Scaling up to 2048 will
use about 1.2M of RAM for really large restores.  This is acceptable
for the 48% function call reduction and the 10% runtime improvement
seen.