Do not pass undefined values to Context.javaToJS(), it converts it to string "undefined" (yuck!)
Do not pass undefined values to Context.javaToJS(), it converts it to string "undefined" (yuck!)

Semi-fixes issue #72

ringo/ringojs,ashwinrayaprolu1984/ringojs,Transcordia/ringojs,ringo/ringojs,ringo/ringojs,Transcordia/ringojs,ashwinrayaprolu1984/ringojs,ringo/ringojs,oberhamsi/ringojs,ashwinrayaprolu1984/ringojs,oberhamsi/ringojs,Transcordia/ringojs,oberhamsi/ringojs,Transcordia/ringojs,ashwinrayaprolu1984/ringojs