adding some const, replacing randNorm with a cosine free variant to be more platform independent, refs #21, #12

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@17362 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
adapting to new randNorm, refs #21

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@17363 29f149b2-0c63-11e1-8f5c-a347f6a9acd0