VE-1312: Blur contentEditable node while destroying surface.

https://gerrit.wikimedia.org/r/#/c/144089/

This solves problem in FF - cursor remains being visible
after canceling edit and switching back to view mode.

Also a fix for accidently comited conflict.
Merge pull request #4059 from Wikia/VE-1312

VE-1312: Blur contentEditable node while destroying surface.