Move sig proc stuffs to sigproc.h
Move sig proc stuffs to sigproc.h
Put playback options in settings dialog
fix dftlen according to winlen; prepapre spinbox for oversampling factor
Add action to hide grids
Add action to hide grids
Check sdif tmes
Manage unspported SDIF data
simplify the cursor in order to make the spectrum plot quicker
Reduce dereferencements
limit spectrum drawing to invalidated rect
simplify waveform drawning