Add -fPIC in intelligent way to build system for 64-bit builds
Rationalise use of powf etc. vs pow
Add spectral_flux
Add geometric_mean
Add spectral_mean, spectral_deviation, spectral_geometric_mean etc.
Add weighted temporal features as per Peeters (xtract_weighted_mean etc) weight given as argv?
Improve noise robustness of xtract_f0
Fix xtract_hps - it doesn't work!
Add Pure Data help file
Add delta functions
Add Max/MSP external example
Check and add return values as appropriate. Make them more sensible!
...do other stuff and eventually...
...optimise!