* [NOD-172] Port EMCH from bchd
* [NOD-172] Fix hdkeychain.TestErrors and add btcec.TestRecoverCompact
* [NOD-172] Make ECMH immutable
* [NOD-172] Fix gofmt errors
* [NOD-172] Add TestMultiset_NewMultisetFromDataSlice and fix Point to be immutable
* [NOD-172] Fix gofmt errors
* [NOD-172] Add test for checking that the Union of a multiset and its inverse is zero