P25 LSM decoder work in progress. Adds a CQPSK decoder based on Max's (KA1RBI) scope.py and gardner loop.

The CQPSK decoder is starting to take shape, but needs more tweaking and testing.  It's not keeping a good lock on strong P25 signals.  I have to add some more features to the intrumentation package to allow me to visualize the internals of the CQPSK decoder so that I can get a better sense of what needs fine tuning.

The CQPSK decoder may work for anyone that wants to sync the repo and run the build script.

src/dsp/am/AMDemodulator.java

@@ -18,8 +18,8 @@ public class AMDemodulator implements Listener<ComplexSample>, RealSampleProvide
     {
         float demodulated = (float)Math.sqrt( ( sample.real() * 
 				sample.real() ) +
-			  ( sample.imaginery() * 
-			    sample.imaginery() ) ); 
+			  ( sample.imaginary() * 
+			    sample.imaginary() ) ); 
 
         if( mListener != null )
         {