Add OG_SAND1.dat object (#27)

* Add OG_SAND1.dat object

Replacement object for SAND1.dat (sand sprites).
Includes 4 more variation sprites over vanilla and 4x likelihood for variation appearance

* small improvements to variation sprites

* Use OG_LSBROWN.dat as CliffEdge

Change object to use OG_LSBROWN.dat instead of vanilla LSBROWN.dat

Author: shusaura85