MDL-40595 tool_behat: Referencing init.php script

Almost everybody will use init.php instead of
running manually the composer commands and util.php
to install and enable the test environment.
MDL-40315 behat: Performance improvement

We look for exceptions after each step, this patch
includes a pre-checking query to avoid multiple queries
for each step when most of the time they are not necessary.
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.
MDL-40295 wiki mod: fix set_url() error for printer friendly page.
Additionally, fix wiki pagelayout for printing
MDL-40589 - Theme/CLEAN - Flip YUI3 tree item icon in RTL mode in folder resource
MDL-40544 - Right align all tables (system wide) in RTL mode (theme/clean , bootstrapbase)
MDL-40189 - Theme/Clean - Right align form labels and left align form input elements on admin pages, system wide (when in RTL mode)
MDL-39704 - Properly align and widen the chat bubbles in mod/chat, when in RTL mode
MDL-40071 - Right align category titles and usernames in gradebook (theme/clean, bootstrapbase)
MDL-40082 - Several UI fixes for question chooser dialog, when in RTL/LTR modes (theme/clean, bootstrapbase)
MDL-40642 set more restrictive umask and use proper permission for new dirs and files
MDL-40642 use this->cfg in local file store when fixing permissions
MDL-20609 quiz tables: improve layout for long cell contents.

By allowing more wrapping.
MDL-40480 tablelib: specify charset in XHMTL downloads.

Thanks to Jürgen Zimmer for the suggestion.
MDL-40719 pluginfile.php: the file API is now stable, so hide debug.
MDL-40785 question instances report: ignore subquestions

We should not count subquestions of cloze questions (parent != 0) but we
do want to count random questions (parent = id).
MDL-40627 add 2G extramemorylimit option to admin UI and use the same units in config-dist.php to prevent confusion

Credit goes to Julien Boulen, thanks for spotting this.
MDL-40796 do not require city and country when uploading users
MDL-40679 mark zlib extension as recommended
MDL-40801 import latest jQuery and jQuery UI