To reduce the number of calls to UpdateText(), the value returned is now
buffered. This fixes bug #443.
* SetValue() now calls UpdateText() and also invalidates the region where
that label is drawn.
* In asynchronous mode, B_NO_POINTER_HISTORY is set now for tracking.
* Increased minimum snooze time in synchronous mode.
* Minor cleanup, renamed fMinLimitStr to fMinLimitLabel, etc.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17146 a95241bf-73f2-0310-859d-f6bbb57e9c96