The updater is using "before update" repair steps and "regular" repair
steps.
The "regular" repair steps are also used by the CLI tool.

Currently no steps exist but can be added later in the static methods in
the \OC\Repair class.

Added unit test to test messaging, error and exception cases.

This also makes it possible to unit test each repair step class
individually

This reverts commit 482eded8, reversing
changes made to 354cace1.

Added check and cleanup for storage/filecache

drastic speedup for nested ldap groups

fix liskov substitution principle in admin mail template settings

Some tests don't clean up the file cache and sometimes entries are
reused by mistake in subsequent test suites.

This cleans up the file cache and storage after every test suite and
also shows an annoying warning.

Issue/8996 IE8 issues with the new menu 

handle http accept headers more gracefully

Fix #8996

Changes a function call in getUserGroups to only retrieve group ids instead of objects.
this change significantly improves performance when using owncloud with many groups, e.g. nested ldap hierarchy (1.2.840.113556.1.4.1941), since getUserGroups gets called in oc_share::getItems, which is needed for every page request.
in my particular case, it took more than 10s to load the calendar page and more than 6s to load the file page.
this was in an environment with 100 user groups (nested) per user. The performance was bad due to the following call stack:
self::getManager()->getUserGroups($user)
  - getGroupObject() (executed for every group!)
     - groupExists() (resulting in many ldap-requests)
since the groups are loaded from ldap, it is unnecessary to check whether the group exists or not.

add a function getUserGroupIds for retrieving group ids instead of group objects. this significantly improves performance when using many (nested) groups.

Fixed array_combine for PHP 5.3

disable failing tests

Save the permissions in the filecache if it's not saved yet

Sometimes etags contain a "e" character which makes PHP believe it's a
number and make the tests fail

Added ORDER BY to enforce share entry order

Sometimes MySQL decides to return the shares in the wrong order, but
some parts of the code seem to require the order to be known, at least
so that the parent shares come before the children shares.

This fix adds an ORDER BY clause to force the order by id.

Fix failing tests on master

make text preview backend use imagettftext, fixes #8087

Disable snapper init for IE <= 9

Snapper doesn't work at all for IE8 and IE9 and messes up with the main
container layout when enabled.

This commits disables snapper for these browsers.