remove superfluous PBD/ARDOUR:: init calls

this reverts 339670b
fix meter scale colors (meterbridge)
more DEBUG::Butler output, formatting corrections, and a warning on cerr if capture/playback buffers are too full/empty
add set-session-extents-from-edit-range
update_time_selection_display should work when in smart mode
add DEBUG_THREAD_SELF to allow use of DEBUG_TRACE with thread IDs on both normal pthreads platforms and PTW32
use correct conditional to choose between different DEBUG_THREAD_SELF macros
add sndfile I/O test application, used for testing disk bandwidth for writing audio files
remove unnecessary sleep
Use DEBUG_THREAD_SELF when using DEBUG_TRACE with pthread IDs

(supports both normal pthreads usage and PTW32)
Fix crash if new tempo is set to start at bar #0
Fix crash if new tempo is set to start at bar #0 / Follow-up for non movable tempos
Fix crash if new tempo is set to start at bar #0 / Follow-up for non movable meters