add half-sample option to pad_signal_1d & fix symmetrization (negative part)
make wavelet_2d use pad_signal_1d
split out conv_sub_2d from conv_sub_unpad_2d
add resolution to 2d scattering & incorporate when calcualting wavelet_2d
fix unpadding bug
make wavelet_1d output absolute resolution, not relative
(un)pad_signal_1d -> (un)pad_signal
make morlet_filter_bank take any input size, rounds up if necessary
ditto for morlet_filter_bank_2d