Previously, I had translated the existing levelhold behavior in
WHMHammer's tja parsing code, assuming that it would produce the correct
behavior for fumen charts. However, that is not the case -- the behavior
is completely wrong.
So, this PR takes out all the old `flag_levelhold` behavior and instead
properly sets the `branch_info` bytes whenever #LEVELHOLD is present on
a branch.
This PR also prepares `shoto9.tja` for further testing, but I'm leaving
that for later...
Fixes#52.
c0442f3721