MDL-42884 core_user: fixed issue when deleting users with invalid emails throws invalidusername exception
MDL-42582 Availability: Restriction display incorrect for multi-para Labels

When a label has multiple paragraphs, its name (converted to plain text)
contains a line feed. Due to an error in regular expressions that don't
accept the line feed, this caused incorrect display on the course page
when that label is shown as a requirement for accessing another activity.
Merge branch 'm26_MDL-41695' of git://github.com/danmarsden/moodle into MOODLE_26_STABLE
Merge branch 'MDL-42808-master' of git://github.com/FMCorz/moodle into MOODLE_26_STABLE
MDL-42880 quiz settings: remove unnecessary disabledif rules.

These rules were causing problems in the case where the form was
sumitted with validation errors. In that case, the During the attempt ->
The attempt checkbox was becoming unset, and hence the other During the
attmept checkboxes became disabled, and the values were not saved.

Thanks to Sam Marshall for suggesting this fix.
Merge branch 'MDL-42100_master' of https://github.com/markn86/moodle into MOODLE_26_STABLE
Merge branch 'MDL-42853-master' of git://github.com/FMCorz/moodle into MOODLE_26_STABLE

Conflicts:
	theme/bootstrapbase/style/moodle.css
MDL-42184 bootstrapbase: popup should have no header
MDL-42852 lib: Blocks disappear in Clean in RTL.

Conflicts:
	theme/bootstrapbase/style/moodle.css
MDL-42852 theme_bootstrapbase: fixed whitespace
MDL-42865 Make XMLDB foreign key check more robust.

Otherwise, installing one bad add-on can completely break this report.
MDL-42863 make capabilities overview more fault-tolerant.
MDL-42774 JavaScript: Ensure that shifter cleans build directories before running
Merge branch 'w47_MDL-42612_m26_paypalruble' of https://github.com/skodak/moodle into MOODLE_26_STABLE
MDL-41316 tool_spamcleaner: Fix sql queries

AS keyword is not allowed in sql qeries for table alias as Oracle doesn't support it
Thanks to Sara Cenni for suggesting the patch
MDL-40223 SCORM: pass limit into function instead of hardcoding to allow cross-db
MDL-42850 administration: Updated bulk user upload errors to be more descriptive.
MDL-42553 core_calendar: third party calendar types can now be uninstalled
MDL-42905 Backup progress: Pointless line of code should be deleted
Merge branch 'm26_MDL-40223' of git://github.com/danmarsden/moodle into MOODLE_26_STABLE