work on cmb, fsspec, xc
- mmap now accepts image input which will reduce the
  current code and make mappin images simple
- azmean function added so I don't do this incorrectly
- cmb profile struct no longer includes correction info
  which dramatically lowers the size of the struct
- plot_cmb_pdf now has color inputs
- map_cmb_profiles now maps profiles 27deg back rather
  than 44deg as this better reflects the region of
  lower mantle sensitivity for profile measurements
- map_cmb_profiles has a colormap input now
- added ax2funits function to aid with annotation work
- added getpeaks function (used by new correlate) that
  is far faster than Matlab's findpeaks
- new correlate functions under development in forge
  - correlate function is 2x faster at normal correlation
    and as fast or faster for correlogram peak finding
  - rotate_correlations is altered for split input/output
    (poorly tested & probably slower)
  - split_horz_correlations & split_auto_correlations
    help separate correlation datasets as needed
- reverse_correlations now flips a & f and t0 & t1 fields
- continued development of fsspec functions
  - planewave codes now handle records with all zeros
  - abs amplitude issues are still present
  - avg option is now properly implemented for arfhorz
  - geo* functions still need work
- numerous bug fixes, documentation updates
  & flexibility improvements not detailed here