adding code to set tile size: needs more work| need to change its location
adding refactored changes to support zooming: refactored to put other code in proper files
adding controllers for zoom and implementation for css based zooming
changed stlye for zoom controller
merged with current changes on master to fix tests
adding stylesheet changes for zooming in and out
adding style for min-zoomout
js code for zooming in and out: Sprite size issue remains
zoom feature enabled for the grid
fixed max and min zoom bug
adding changes for merging