Complete alignment of platform agent platform driver and RSN platform driver

- common interface at the PlatformAgent level (removed all more specialized operations here; instead they went to the driver level) 
- moved specific functionality to the driver level, in fact, most of which now in RSNPlatformDriver, with some very basic and common driver functionality in the PlatformDriver class (mainly related with unconfig/disconn/connected states). 
- all "get" operations now via get_resource while all "execute" ones via execute_resource.

All tests passing locally:

    Blame Report on left over objects in couchd db
    ====================
    Process leak report
    Test Leaked Processes
    ==== ================
    ----------------------------------------------------------------------
    Ran 53 tests in 810.216s
    
    OK (SKIP=1)
    Shut down cc process
    	Closing container with pid:35337