(i.e. 'lib/ardour3' or 'lib/mixbus3' as appropriate) These changes are MSVC specific and shouldn't affect the other builds
(new preprocessor directive - greatly improves CPU loading)
It'd be nice if we could use 'ARDOUR::config_dir_name' for this purpose (or perhaps 'PROGRAM_VERSION'). However, neither is implemented widely enough at present to make this practical. Keep an eye on them though, as possible future strategies.
