6.2 simultaneous inline editing bugs

Hi,

Simultaneous editing of the same content block by two different users is still possible, resulting in loss of edited content, or row-not-found: GenericOID errors.

1. Frontend inline editing & frontend inline-editing of the same content-block is possible, resulting in loss of content and pop-up-loop.
2. Frontend inline editing & backend inline-editing of the same content-block is possible, resulting in loss of content.
3. Frontend inline editing & frontend inline-editing of the same shared content-block is possible, resulting in GenericOID row not found error.

---
When in front-end inline editing mode, Sitefinity should 'disable' a language selector dropdown.
While it doesn't switch to the language variant, it still lets the editor/user believe it did.