The IDE include checker got to the point where it is actually useful and
this removes a lot of unneeded includes.
Naturally, especially for headers like util.h, this may mean we need to
re-add includes in consuming cpp files that bloats the diff a bit.
The mining code still called that, this replaces it with standard
log lines that cost less at runtime and keeps the code that is
rarely run away from the shared parts.
This introduces a new BlockHeader helper class which Block and
MutableBlock can both produce, which helps a lot of methods to
be ported to no longer be dependent on us using a MutableBlock
object, which is too costly to use when we have no intention
to alter the block.
This follows the coding style guideline that the file that contains a
class should follow the exact name of this (main) class.
pubkey.{h|cpp} -> PublicKey.{h|cpp}
pubkey_utils.{h|cpp} -> PublicKeyUtils.{h|cpp}
These are technically static libs, but not in any way shared libs.
They are used solely only by this repo and really only by the hub.
Most important, no header files are installed and basically none of
the normal rules for reusable libraries are applied to these files.
tomFlowee