[TASK] Octaves bands computation

 - fft moved into the new C file equalizer.c
 - added new option for control of the number of Octave bands within the range from
   1/1 to 1/24 (meaning about 9 to 243 bands is allowed to be control)
 - plus another mess added to Makefile...
[TASK] Virtual knots

 - work on control of virtual program knots of Octave bands
 - new option for control of these knots
 - added prototypes for band control