Changed the pastebin element to <body>. This seems to fix the problem but makes the inline toolbar to "jump" on paste.
Position pastebin according its offsetParent; bypass impossibility to get offsetParent from body element.
Do not position pastebin according to editable if it is a body element.
Cancel blur when moving selection to pastebin to avoid selection locking.
Changelog.
Merge branch 't/10644'