* ECDKG protocol prototype
* added test for enc/dec math
* get rid of decryption_session
* added licenses
* fix after merge
* get rid of unused serde dependency
* doc
* decryption session [without commutative enc]
* failed_dec_session
* fixed tests
* added commen
* added more decryption session tests
* helper to localize an issue
* more computations to localize error
* decryption_session::SessionParams
* added tests for EC math to localize problem
Svyatoslav Nikolsky