b98c489066 hashes: Move from_engine functions (Tobin C. Harding)
Pull request description:
In order to use the `general_hash_type` macro the must exist a standalone `from_engine` function. Currently this function is in different places in different modules. In an effort to make the `hashes` code easier to reason about put the functions right below the macro.
Code move only, no other changes.
ACKs for top commit:
Kixunil:
ACK b98c489066
apoelstra:
ACK b98c489066e8916a383099e5037e5a24832548ba; successfully ran local tests
Tree-SHA512: 8dfbf2b422d078d687708fa94a478ca597fae141f5c1f0a318a36152ca33f4760bb0545ab67523c558a8c3b8d258356975c5e357600d0ac980d473250a2af20e