Merge pull request #1 from nhazar/master

Add LFP wavelet filtering
Tweak wavelet filtering
More wavelet filtering tweaks
Clear approximation coefficients more efficiently on nigma's suggestion
Docs
Make lowhigh methods return power ratio instead of separate bands
Make plot kwarg trigger plotting in lowhigh methods
Better 66 Hz detection logic
Restore saving bin times in BinaryCode.calc()
Weight spike correlations by LFP power ratio
Swap code blocks in CodeCorr.calc
Weight means as well in CodeCorr.calc, possibly more reasonable
Rename lowhigh_fourier() --> lowhigh()
Rename lowhigh* --> pratio*
Docs
Bind InternalParams directly to Experiment
Fix powerplot() text placement
Check for and replace zero power values before converting to dB
Plot by default in pratio* methods
Fix timescale of LFP specgram() and powerplot(), should coincide with plot()