make one of the cubes in two_cubes.sdf static (immovable) using the <static> tag in SDF

add an example using 'direct'
fix the send-desired-state commands, to add flags for arguments set, using default values.
Start exposing SDF loading in shared memory api, not fully implemented yet.

examples/SharedMemory/PhysicsClientExample.h

@@ -4,7 +4,7 @@
 enum ClientExampleOptions
 {
 	eCLIENTEXAMPLE_LOOPBACK=1,
-	eCLIENTEAXMPLE_DIRECT=2,
+	eCLIENTEXAMPLE_DIRECT=2,
 	eCLIENTEXAMPLE_SERVER=3,
 };