MDL-27767 install: Shows notifications rather than throwing exceptions when installation encounters unexpected id for guest or admin
MDL-27143 question bank: questions not saved when deleting a category.

Based on a fix by Nikhil Gupta.

Conflicts:

	lib/questionlib.php
MDL-30498 user name can overlap user report icon.
MDL-30677 quiz: fix attempt counts when a student is in several groups.
Automatically generated installer lang files
MDL-30689 qtype base: fix typo in extra_answer_fields code.
MDL-28180 backup - set excluded activities for any non-course operation
MDL-28180 backup - take rid of dupes in course_completion_aggr_methd
MDL-28180 backup - on restore always prevent completion_aggr_methd dupes

This covers the last case where dupes could be happening in the
completion_aggr_methd table: Restoring one complete course into
an existing one, adding information. Now we always check if the
aggr_method exists before inserting it.
MDL-29195 Remove duplicate Participants -> Notes from navbar
Merge branch 'MDL-28180_20' of git://github.com/stronk7/moodle into MOODLE_20_STABLE
MDL-29239 fixed edit course setting for moodle/course:changesummary permission is set to prevent.
MDL-30463 lesson module: add space between yes and no options on start last attempt page
Merge branch 'MDL-27143_20' of git://github.com/timhunt/moodle into MOODLE_20_STABLE
Merge branch 'MDL-30498a_20' of git://github.com/timhunt/moodle into MOODLE_20_STABLE
Merge branch 'MDL-30677_20' of git://github.com/timhunt/moodle into MOODLE_20_STABLE
Merge branch 'MDL-30689' of git://github.com/timhunt/moodle into MOODLE_20_STABLE
MDL-30653 Remove duplicate Participants link from navbar
MDL-305439 - BLOG - Adding RSS link to user blogs
MDL-30575 more mail header cleanup