Libsharp reference updated.
bug fix: vol not in space._meta_vars; space.get_power_indices prepared.
get_power_indices sketched; gfft dependence from smoothing removed.
get_ & bin_power_indices added; test version; TODO: redesign index handling.
dict useage nolonger deprecated.
set_ and get_power_indices implemented; TODO: adjust calls.
power_indices fully incorporated.