Towards MIDI:

Towards MIDI:

- Converted vector<Sample*> to BufferList and numerous counts from int to ChanCount (and related changes)
- Added fancy type-generic iterators to BufferList, PortIterator (see IO::collect_input for a good example of the idea - the same code will work to read all input (of various types in a single IO, eg instruments) without modification no matter how many types we add)
- Fixed comparison operator bugs with ChanCount (screwed up metering among other things)
- Moved peak metering into it's own object, and moved most of the pan related code out of IO to panner (still a touch more to be done here for MIDI playback)

Not directly MIDI related fixes for problems in trunk:

- Fixed varispeed gain/pan automation to work properly (was reading the wrong range of automation data, probably causing nasty clicks?)
- Fixed crash on varispeed looping (possibly only a 64-bit problem).  It still doesn't work, but at least it doesn't die

Quite a few things broken, and the new classes are pretty filthy still, but I think the direction is a lot better than all my previous plans...

git-svn-id: svn://localhost/ardour2/branches/midi@795 d708f5d6-7413-0410-9779-e7cbd77b26cf