Initial whack at moving the port tables to the plugins themselves, whilst
trying to get the host out of the business of managing that stuff...
Revert "Begin the process of consolidating running a track down a single function"

This reverts commit d40a072d230621494d0793bb8956de50af355bd1.

This was purely a refactoring to future-proof the code for the next major
version of PyDAW, but it created a god-awful dropped notes regression...
Revert for now to fix the problem, I'll try again later to do the
track-type consolidation...