Check the file names upon synchronization if there are multiple results (see #5644)
Inject the command scheduler script inline to reduce the number of JS files
Add the Zend OPcache to the `Config` class
Do not trigger the "setNewPassword" hook twice (see #5247)
Fix the anchor `class` attribute in the tree view

Single HTML element attributes must be separated by whitespace characters. In the tree view, that is currently not the case for the default button operation's `class` attribute, thus making the markup invalid. The present patch fixes the issue.

Signed-off-by: xchs <github@gmx.net>
Fix an unescaped ampersand in the `PageTree` widget (hopefully the last one)

Signed-off-by: xchs <github@gmx.net>
Added the "initializeSystem" hook (see #5665)
Merge branch 'hotfix/class-attribute' of git://github.com/xchs/contao-core into develop
Rename the `editmeta` key to `editheader` (see #5668)
Correctly detect open HTML tags in `String::substrHtml()` (see #5669)
Update all language files
Version 3.1.RC1