[BUG] Move element set the wrong language

[gamerxl]

Summary / Description

Moving a content element of language "All languages" after another content element set its language to the language of the content element it was moved after.

Version

Current version 2.0.3 and lower.

Steps to reproduce

1. Create an empty page.
2. Create a content element with language set to "All languages".
3. Create another content element below the just created element. Keep the language just as it is of the current language column. E.g. "German".
4. Move the first content element after the second.

Expected behaviour

The moved content element keep its language set to "All languages".

Actual behavior

The moved content element get its language set to the language of the content element it was moved after.

Additional

Possible fix

Use the language handling from drag and drop implementation for page layout from the TYPO3 CMS core.

Fixes Kephson#4

Miscellaneous

If a content elements gets moved in a container element then the elements gets "moved" to the "Unused" column and it keep its language set to "All languages". So far I see this behavior is identical to the TYPO3 CMS core - should be ok.