[HRE-Melt] Fully melted province history, painted cultures, etc.

I've also successfully applied all 3 of the melts (low_german_1100, dutch_1150, german_melt_1170) to the character history database.  However, I haven't tested the latest character history melts in-game, so that'll come separately.  Besides, it's going to be a hefty pull request on its own.

I'll send you a couple screenshots of the culture map at different start dates or something.  It's pretty sweet.  The localisation is currently Anglicized, unfortunately, as I'm sure you'd just need to rewrite half the native names for me in the end anyway, if I tried to take care of that too.

The actual dynasty melt spreadsheets have been included directly in the git repository and therefore the mod itself's fileset.  They're in a safe place where CKII won't notice them, however: `SWMH/files/...`