Log Message:
Update contao35 to 3.5.18.

It also welcome back to Danish and Slovenian.

Version 3.5.18 (2016-10-25)
---------------------------

### Fixed
Correctly "toggle select" nodes that are loaded via Ajax (see #8535).

### Fixed
Show running events in the event list again (see #8497).

### Fixed
Correctly calculate the maximum length of tl_files.name (see #8536).

### Fixed
Correctly add the headline if a content element is versionized (see #8502).

### Fixed
Optimize the DCA sorting filter for date fields (see #8485).

### Fixed
Do not show version entries of deleted files (see #8480).

### Fixed
Redirect the empty URL depending on language and alias name (see #8498).

### Fixed
Apply `specialchars()` to widget attributes (see #8505).

### Updated
Updated the Ace code editor to version 1.1.9.

### Fixed
Handle special characters in passwords when creating an admin user (see #8512).

### Fixed
Queue the requests when rebuilding the search index (see #8449).