Boolean params

ping @mgrauer This fixes #90 that you reported. PTAL
Nicee ! 

Remind me of the early Midas days :) 
See http://public.kitware.com/gitweb?p=MIDAS/Midas.git;a=blob;f=vendors/kwutils.php;h=8c57d552e264ba4b309383079976b8b5759fed3f;hb=HEAD#l1546