Merge pull request #341 from virtual-world-framework/mars-game-staging

merging
Fixes the pointer event point calculation relative to the stage
Make the drawing names unique per session
Merge pull request #343 from virtual-world-framework/branch/drawing-naming

Make the drawing names unique per session
Removed recursive call to nextStep
Reduce the number of getProperties in animationTime.get
Reuse property values in heightmap.js to reduce getProperty calls
Clean up heightmap interface a bit