Instead of generating a private file on send that needs to be
provided again in finalize, the private context information is
saved in the wallet db.
Also move internal Context to bona fide libwallet type
* First pass at restructuring the keychain crate and introducing a Keychain trait
* Parameterized everything that had to. Stuff compiles.
* More stuff compiles, fix most tests
* Big merge, pushing down opening the keychain forced adding factory methods on trait
* Test fixes for pool and servers crate
* remove context object from aggsig and transaction libs
* fix to aggsig, and remove unnecessary warnings
* put tx_fee function into libwallet::transaction
* Error cleanup, and creating libwallet error type
* remove some unwraps
* checker bug
* ensure transaction tests checks sender's wallet
* Beginning to rework aggsig library workflow
* more refactoring of transaction api
* whoever does round 1 first creates offset
* slate finalisation now context-free, so anyone can do it
* remove concept of transaction phase
* remove slate phase enum
* update actual send/receive code with new transaction lib workflow
* beginning to refactor keychain into wallet lib
* rustfmt
* more refactor of aggsig lib, simplify aggsig context manager, hold instance statically for now
* clean some warnings
* clean some warnings
* fix wallet send test a bit
* fix core tests, move wallet dependent tests into integration tests
* repair chain tests
* refactor/fix pool tests
* fix wallet tests, moved from keychain
* add wallet tests
Ignotus Peverell