Transceiver52M: Output device and operating mode to stdout

Very useful user information at startup.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
Transceiver52M: Create new osmo-trx executable

Create new main executable with full command line option parsing
of relevant parameters. Database configuration table still exists
(and must exist because of the global gConfig object), but can
be bypassed with command line options.

Signed-off-by: Thomas Tsou <tom@tsou.cc>
Transceiver52M: UHD: Check running status before stopping stream

On startup errors we get a segfault if we stop and shutdown. This
is because we try to send a stop stream command to the device before
it has been created. Setup a check for running status before
attempting to stop the physical device.

Signed-off-by: Thomas Tsou <tom@tsou.cc>