Fix an issue with style.ini replacements values not having relative
locations corrected, when those values are "url(...)".

Explanation:  In the change to the less css extension, variable
replacements now happen after the less/css files are processed
for correction of relative locations.
Merge pull request #421 from splitbrain/FS#2879

FS#2879, relative url() values in style.ini replacements not being adjusted