[ESS] iESS - consistent string formatting within single and double quotes

[Aleksandar Blagotić]

This one's bugging me for a while, and I never seemed to care about it
much, until recently. As you can see in this image
(http://i.imgur.com/w3JSH.png) the buffer on the left hand side
formats strings within single quotes "properly", while I can achieve
the same result in iESS buffer only for strings in double-quotes. I
rarely use double quotes, unless I want to avoid escaping quotation
marks. I reckon that this is an easy one, but currently I have no clue
on this one. Any ideas?


aL3xa