feat #972 prefix URLs in CSS templates

This commit introduces the possibility to define a method to be used to prefix all the image urls inside css templates.
LCRange Handler Fixes to allow comma pattern
feat #964 Changes for Error tooltip on keydown

close #964
fix #973 Fixing the test because was failing on IE7

Test failing on IE7
fix #974 test.aria.utils.cfgframe.AriaWindowTest failing on IE 8

Commit 2c1141e33deb90e8a5c5cd10676d87b486dd22c4 makes the following
test fail on IE 8: test.aria.utils.cfgframe.AriaWindowTest.
It only happens on a true IE 8 (not on IE 11 in IE 8 mode).

The issue comes from an "Unspecified error" raised when trying to read
Aria.$window.document.activeElement. This commit surrounds that piece
of code by a try ... catch.
1.4.16