MDL-45699 behat: can now use alt cache config
MDL-45699 cache: acceptance test improvements

We now use the unit test cache config class when running
acceptance tests so that the same defines are applicable there.
MDL-45699 cache: renamed cache_config_phpunittest

Renamed cache_config_phpunittest to cache_config_testing
MDL-48568 cache: stores now determine testing

Cache stores are now responsible for deciding if they are suitable
for use as the primary cache store during unit and acceptance tests

Changes are as follows:
* New method: cache_store::ready_to_be_used_for_testing
* Core cache store have been updated to override this method as
  required.
* MongoDB usesafe default changed to true to match actual default
  behaviour.
MDL-48213 filter_algebra: Allow cookies in debug script
MDL-48224 cron: Buffer SMTP connections around tasks
MDL-48088 calendar: normalize DTEND, add romance standard time

Thanks to Cedric Mortiers (cmortiers@stjohns.be) for providing the patch.
MDL-48580 report_log: fix site errors dropdown

Thanks Renaat Debleu for pointing this bug and share a solution.
MDL-48593 messageinbound: Correct header retrieval from IMAP server

Header retrieval should only be performed on the base message, and not each
part of the message as is currently performed.

This came to light because Google changed their IMAP server such that, if
you inform the data query that you wish to retrieve the headerText for a
part which does not contain a MIME header, then no message is retrieved in
the search causing a general failure of the IMAP fetch.

In normal circumstances, headers should only be a part of the base message
part.
MDL-48534 mod_assign: display correct workflow state and marker
MDL-48591 calendar: Mini Cal Display DST Events
MDL-48638 database SQL: Fix typo in exception constructor
MDL-48653 behat: Steps to click and dismiss a dialogue.

We already had the corresponding
    I click on "Home" "link" confirming the dialogue
but I needed the opposite
    I click on "Home" "link" dismissing the dialogue
MDL-48421 navigation: correctly load child categories if parent is loaded
MDL-48421 navigation: accounting for potential regression
MDL-48213 filter_algebra,filter_tex: Require sesskey for debug actions
MDL-48062 atto_image: Add image select on single click
MDL-48483 admin: attached color label to input control
MDL-48639 behat upload: support absolute paths & better errors

In a custom step I needed to be able to upload a file I had previously
saved to $CFG->dataroot/temp, but that was not possible.

Also, the failure was not at all obvious. I have made it throw a clear
exception if the file you are trying to upload does not exist.
MDL-48666 quiz: let JS to get a Qs slot number on the summary page