add OFDM components based on liquid-dsp
Updating spectrogram and adding spectrogram display controller
Merge pull request #7 from andrepuschmann/next_liquid_fresh

add OFDM components based on liquid-dsp
Minor edits to Doxygen file paths
Adding polyphase filterbank channelizer and sythesizer using liquid-dsp
Adding support for dynamic reconfiguration of subcarriers, prefixlength and taperlength
Adding to requirements list
Updating version number for next release
Merge pull request #19 from suttonpd/master

Adding OFDM and polyphase filterbank channelizer components using Liquid-DSP