[REVIEW-3-6] fix for fdo#46250

[Noel Power]

This patch makes lessens the strictness when determining when paste & 
special-paste can be applied, please consider
http://cgit.freedesktop.org/libreoffice/core/commit/?id=d27a7b8c5b96eb328918cc67b9b5562b8870f2ac

for cherry-picking to 3.6.

Kohei, my initial gung-ho-ness for additionally squashing the paste 
always on behaviour has waned a little, if we do that I'd prefer to do 
it separately. ps. in the commit message I forgot to mention the bug 
number, if cherry-picking please do a git commit --amend to add it 
before pushing, thanks

Noel