Big thanks to Siobonbon for finally clearing up the muck that had been
sitting around for so long 👍
The mysterious dex flags are much clearer now, there is no 'via trade'
flag (it's the forms owned flag)
Remove numerous inter-form dependencies, remove hard-coded offsets,
update a few spots to use better programming practices.
Should increase the readability of PKHeX's source code.
Shouldn't call setup methods after setup is complete; I extracted all
necessary operations that need to be repeated (loading the bitflags)
into a separate method.
Thanks ShaKage!
