cleanup include of assert.h
rpc: Compute number of confirmations of a block from block height

Currently this uses a CMerkleTx, but that makes no sense as we
have the CBlockIndex available. As noted by @jgarzik.
Move CMerkleTx to wallet.cpp/h

It is only used by the wallet so it has no place in main.
Merge pull request #4788
Merge pull request #4778
Replace weird characters by normal spaces
Merge pull request #4781

187115c cleanup include of assert.h (Philip Kaufmann)
Merge pull request #4789

bac5586 Replace weird characters by normal spaces (Pieter Wuille)
changed field types in some structures to equivalent unambiguous types

Conflicts:
	src/core.cpp

Rebased-By: Wladimir J. van der Laan
Github-Pull: #4180
Remove unused function StackString() and class CCoins;
Discover some missing includes
Rename script.h/.cpp to scriptutils.h/.cpp (plus remove duplicated includes)
Move CScript class and dependencies to script/script
Separate script/interpreter
Separate script/standard
Separate CScriptCompressor
Separate script/sign
Move scriptutils.o to wallet
Move CAffectedKeysVisitor to wallet.cpp (remove ExtractAffectedKeys)
Rename scriptutils.o to wallet_ismine.o