replace u_scanner with DECORATE compatible version

[rfomin]

Preparation for MBF25 DECORATE implementation, which requires more sophisticated scanner. Adapted from https://bitbucket.org/Blzut3/declarate/src/master/src/scanner.cpp

• Small refactoring of UMAPINFO.

The KEX port's masterlevels.wad has a different map order than our base/masterlevels.wad/umapdef.lmp. Should we remove all UMAPDEF at this point?

[fabiangreffrath]

Please update README.md as well.

[rfomin]

Done in fb64425

[fabiangreffrath]

The KEX port's masterlevels.wad has a different map order than our base/masterlevels.wad/umapdef.lmp. Should we remove all UMAPDEF at this point?

But this is due to another update to the WAD files, and not related to the parser changes proposed here, right?

[rfomin]

But this is due to another update to the WAD files, and not related to the parser changes proposed here, right?

Yes, it's not related to this PR, I'm just starting to refactor UMAPINFO a bit more locally. I think we should remove the whole UMAPDEF system at this point: popular versions of nerve.wad and masterlevels.wad now have proper UMAPINFO, also we have the woof.pk3 system now, so load order is not such a problem.
The UMAPINFO refactoring would be a separate PR.

[fabiangreffrath]

Alright, please proceed.