minor license, header end comment etc. cleanup in /script

- ensure all licenses are just MIT
- add a missing header end comment
- ensure alphabetical ordering
fix a lock indentation in main.cpp

- also ensure alphabetical ordering in file header
Merge pull request #5049

4dc5eb0 fix a lock indentation in main.cpp (Philip Kaufmann)
5eed8c2 minor license, header end comment etc. cleanup in /script (Philip Kaufmann)
script: move CScriptID to standard.h and add a ctor for creating them from CScripts

This allows for a reversal of the current behavior.

This:
CScript foo;
CScriptID bar(foo.GetID());

Becomes:
CScript foo;
CScriptID bar(foo);

This way, CScript is no longer dependent on CScriptID or Hash();
script: remove all uses of CScript::GetID()
script: remove CScriptID::GetID()
script: add base class for serializing core structures for scripts
script: use CScriptBinaryData for all core structures that are added to scripts
script: remove old methods of writing core structures
script: move ToString and ValueString out of the header
script: add a slew of includes all around before removing some from script.h

Lots of files ended up with indirect includes from script.h.
script: drop core includes

The string processing headers are sticking around for now, we may drop them
later.
Replace SignatureHash() with class TxSignatureHasher
Change SignatureChecker constructor and make its TxSignatureHasher a reference