Cosmic-profiles

- Fixes
- create cat and viz directories automatically if missing
- box size read off from Gadget I, II or HDF5 file rather than having to be provided
- much less RAM-heavy
- New Features
- made compatible with Gadget-style I, II and HDF5 files

- Fixes
- unit system confusions resolved by allowing user to define ingoing and outgoing unit system
- New Features
- choosing either dark matter, gas or star particles in Gadget HDF5 snapshots via OBJ_TYPE
- choosing number of mass bins for plotting purposes
- restricting to halos in the index range select = [idx_1, idx_2]

- Fixes
- caching with modifiable maxsize
- ellipsoidal shell based shape estimation had poor if-else condition distinguishing innermost from other shells incorrectly
- density profile model parameter array had somewhat arbitrary ordering, fixed by dictionary
- New Features
- choosing between reduced shape tensor and non-reduced one
- ellipsoidal shell based density profile estimation