xwiki/2.0 renderer should escape any (% it can find

Problem is that for example in

Some text with percent (%).

Another paragraph with percent between parenthesis (%).

(%).<NL><NL>Another paragraph with percent between parenthesis (%) is parsed as a custom parameters block.

This is normal given the way the parser is working and it would be very hard to change that and still support anything in parameters so the solution is to properly escape it.