Added jzmq as a submodule.
Several bug fixes related to multi-channel data collection.

System has been verified in 1,2, and 4 channel collection modes with:
1. Sample rate : 64 MSPS
2. Decimation : 64
3. Receive Window width : 50km (i.e. ~334 usec)
4. PRI : 4ms
Added usrper file to program firmware manually if needed.