* libardour uses ARDOUR::nframes_t and ARDOUR::nframes64_t explicitly in headers

* libardour uses ARDOUR::nframes_t and ARDOUR::nframes64_t explicitly in headers
* use explicit operator<< and operator>> that in turn use PBD::EnumWriter when serializing and deserializing to/from rc files
* adds scrolling in mixer window (from 2.X)
* BBT math stuff - untested, but basically operational
* move LocaleGuard into its own file(s) in libs/pbd
* Tempo now uses nframes64_t everywhere (except for sample rate values)
* as in 2.X, use mkstemp and hack to avoid temp file nonsense, and remove erroneous free() from disk stats output

git-svn-id: svn://localhost/ardour2/branches/3.0@5961 d708f5d6-7413-0410-9779-e7cbd77b26cf