* Add EnumConstIndex
* Get working with discriminants
* Remove unused/(unneeded?) features
* Rename to EnumIndex and index(..). Make const_index conditional
* Get repr(..) working
* Fix issue to support rust 1.32
* Switch from VARIANT# to {ENUM}_{VARIANT} for variant constant names
* Expose constants as part of implementation
* Add discriminant error messages. Cargo fmt my code
* Add rustversion to make compilation conditional on 1.46
* Handle expr discriminants
* Fix generics handling
* Make constants always available. No need to only expose them when const_index is defined
* Change to FromDiscriminant. Only output a single function
* Don't make constants accessible
* Make rustversion a dev dependency in strum-tests due to upstream change
* Cleanup doc tests for const
* Rename to FromRepr/from_repr
