One-third-octave filter bank, including additional inputs and outputs

This m-file was based on oct3bank m-file from Christophe Couvreur. Including some features.

The included features are:
Definition of additional parameters on the imput of the function:
>> Fs, Sampling Frequency [Hz]
>> dBref Reference level for dB scale.
for SPL, Pref = 20E-6 Pascal
>> Fc One Third Octaves Preferences
Ex. Fc = [20 25 31.5 40 ... 1000];

The function returns the <p> values in dB [ref = dBref], and the <f> One Third Octave Frequencies.

Obs. Half of the sampling frequency (Fs/2) must be higher than the superior frequency limit value of the last one third octave choosed as preference input.
Also <Fc> must have more than, at least, 7 third octave values.