- cache filename and database filename now expand home directory `~/`
- support for custom cache filename and directory. default is still
`~/.cache/dftfit/cache.db`. `use_cache` changed to
`cache_filename`.
- adding `MgO` example it is most of the data used for publication
- adding database merge functionallity allowing much easier management of calculations
- fixed bug: parameters are now ordered when using charge constraint
- adding get potential from evaluation
- fixed bug: evaluation to potential does not apply charge constraint correctly
- fixed bug: filter_(evaluation, potential) working properly to select best, random, worst
- fixed bug: correct bounds for contraints. used to be discarded.
- adding ability to easily write potential to file
- adding ability to easily test potentials for static, lattice, elastic
- adding feature to generate relaxed structure from potential
- visualize progress of run `dftfit db progress --run-id=... database.db`
- summarize all of the potential fitting in the database `dftfit db summary database.db`
- adding feature visualize the pair distributions of the training set