[WIP] updated the 2 channel synthesizer to use a more SIMD friendly

filter structure.  Updated the channel results array buffer to produce
reusable buffers.

This has dropped the overall memory usage considerably when profiling.

Resolved issue in the processing chain where polyphase channel sources
were not being stopped and were stacking up in memory.

src/main/java/io/github/dsheirer/module/ProcessingChain.java

@@ -626,6 +626,8 @@ public class ProcessingChain implements IChannelEventListener
             {
                 removeModule(mSource);
 
+                mSource.stop();
+
                 mSource.setOverflowListener(null);
 
                 switch(mSource.getSampleType())