[layer23] Added control features to VTY

[layer23] Added control features to VTY

tx-power: fixed or automatic transmit power selection
(not currently supported by layer 1)

simulated-delay: Make BTS believe that we are closer or at greater distance
than we actually are. This is required to use cells that only allows a limited
range to the mobile. Also it prevents from being tracked by location services.

stick: Make mobile stick to a given ARFCN only. For testing purpose the
cell selection process can be limited to only one frequency. This speeds
up cell selection process.