This change drops the various arguments that force the user to select if
an argument is an .info file or a .db file etc. Instead auto-detect them
and also allow the user to provide a list of arguments.
The most direct effect is that I can now run 'unspent-db info *.info"
Move some globals and all stuff pulling in crypto to the
server/serverutil.cpp file
Remove dead code.
Move several items that were used in only one place to the respective
files using them.
Move the class WaitUntilFinishedHelper into its own file.
Made sure no header includes utils.h
remove a handfull of files including utils.h for nothing.
When pruning we sort leafs by txid / output and refrain from
writing the txid repeatedly for outputs of the same tx.
Additionally, use the fact that we only ever get to a leaf via
a bucket and since the first 64 bits of a txid is there, skip
repeating them when writing to disk.
Last, make pruning have different strategies.
This should shrink the utxo by about 40%