gauss_kernel is deprecated.
Make kernel_size explicit parameter of all kernels
Allow to overwrite kernel_size per per function call.
Reduce duplicate code.

rate_estimation <-> signal_processing
Document smooth function.
Rename ...single_trial to ...trial_pail functions

It's more precise ...
Guard against empty spike trains

in minimum_spike_train_interval.
More clear dummy variable naming.
Typo in documentation.
apply_to_dict
Allow to pass min/max time in interval functions.

(min|max)imum_spike_train_interval
DRY bin_spike_trains.
Deprecated notice for minimum_spike_train_interval

moved to signal_processing
Use max spike train interval in binning.

I think, that makes more sense in general.
Further test for bin_spike_trains.
Merge branch 'feature/dryRateEstimation' into feature/stMetrics