Fix play verification when a seek is queued.
Make LateNight-Stacked to use start_play.

Previously when play verification occurred, it would fail
if the play position was at the end of the track.  But if
a seek has been queued, that should still be allowed.  This was
causing the start_play button to fail every time the
sampler had been allowed to play the whole sample.
When clearing scale, allowing choosing crossfade or not
Fix if statement
Helpful comment
Right click should be start_stop
Right click should be start_stop, fix tooltip
Don't need EmitOnPress or ConnectValue any more
fix the actual bug, which is that reading past the end is ok.
Debug assert if math_clamp is used incorrectly
Merge branch 'master' into start_play_fix
Warn, don't crash, if math_clamp is used badly
Merge branch 'master' into start_play_fix
notify seek was in the right place, leave it there.
Add hercjogfast mapping mode.
This is required to map the RMX2 effect knob without need for scripting.
This results in ~ 2 turns for the complete range.
Without fast addition it was ~5 turns.
FIX:1311359 add close button to dev-mode window

GTK3 does not add close buttons to a dialog window by default. Since
this is not a Dialog which requires input change the window type to
Qt::Window
Merge pull request #193 from cardinot/master

Bug #1197631 fixed - Track properties box expanding badly
Merge pull request #295 from kain88-de/developerCloseButton

FIX:1311359 add close button to dev-mode window
Merge pull request #282 from ywwg/start_play_fix

Fix bad use of math_clamp
Add tooltips for master sync
Merge pull request #293 from daschuer/herc_jog_fast

Add hercjogfast mapping mode.