MDL-47466 calendar: use get_in_or_equal() in function calendar_get_events to fix problem with ORA-01795
MDL-47466 calendar: fixed error ORA-01795 in calendar_get_events
MDL-47930 mod_forum: Display all forum statuses correctly

It is possible for users with the mod/forum:managesubscriptions to
subscribe to forums with subscription disabled. This is handled by
forum_get_subscribe_link() already and should have been handled here all
along.
MDL-47793 assign: Reset reveal identities
MDL-46500 filepicker: prevent error when element does not exist
MDL-46500 mod_data: Removing duplicate filemanager initialisations
MDL-46262 availability: validation of fields without value

Thanks to Tomasz Pawlik | CKO USl for the patch
MDL-48025 user: fixed typo in user_search HTML
MDL-27930 Lesson: the count-down timer does not work
MDL-48035 Merge English strings from the en_fix language pack
Merge branch 'MDL-48035-27-enfix' of git://github.com/mudrd8mz/moodle into MOODLE_27_STABLE
Merge branch 'MDL-27930_27' of git://github.com/jmvedrine/moodle into MOODLE_27_STABLE
MDL-27930 lesson: Remove custom styling from timer
Merge branch 'MDL-47930-27' of git://github.com/andrewnicols/moodle into MOODLE_27_STABLE
Merge branch 'MDL-47793-m27' of https://github.com/micaherne/moodle into MOODLE_27_STABLE
MDL-47793 assign: trivial fix for inconsistent use of get_instance()
Merge branch 'wip-MDL-46262-m27' of git://github.com/marinaglancy/moodle into MOODLE_27_STABLE
Merge branch '48025-27' of git://github.com/samhemelryk/moodle into MOODLE_27_STABLE
Merge branch 'MDL-46500_27' of https://github.com/dmonllao/moodle into MOODLE_27_STABLE
MDL-48019 mod_forum: Add sesskey checks when setting tracking prefs

This also removes set_url() and changes require_course_login to
require_login as guests cannot set tracking.