Character history cleanup

[rquinio]

I think a cleanup of character history and dynasties will be needed at some point, as it's a bit messy:

• [x] vanilla characters are still in the files, generating errors in the validator and masking the real errors. Any character born after 800 A.D. should be removed.
• [x] some characters have a different culture than the name of the file (in particular WtWSMS_character_gift.txt and the like, but also georgian.txt, finnish.txt, dutch.txt, etc.)
• [ ] some characters and dynasties are duplicated (Meroving, ...) causing confusion
• [ ] there's no clear ID range assigned per file/culture, making it easy to have duplicate IDs ?