dqcsk demod now passes the entire correlation value on, not just the phase angle
added new soft demodulator for DQPSK. fixed a mistake in the unit tests that was probably masked by the FEC capability of the channel coding.
added deinterleaver for float values. copies the one for ints exactly.
added soft demapper for codewords. also there are now two versions of the CSS phy - hard and soft decision.
added BER measurement block because the existing solution with tagged streams was inconvenient and didnt perform well. also added scripts to perform BER measurements of CSS and OQPSK PHY layers.