fixed RTT graph. Added colors, and new options to RSGraphWidget. Still needs to draw names for different colors

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7610 b45a01b8-16f6-495d-af2f-9b41ad6348cc
removed unused code

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@7611 b45a01b8-16f6-495d-af2f-9b41ad6348cc