MythUIScrollBar: Initialize maximum to zero until it is actually known,
otherwise the scrollbar is drawn prematurely.

(cherry picked from commit 899f3d3185c994715c86cd42bf56e011266e4c9c)
MythMainWindow::Norm: With very small values of x, scaling down can cause
the 'normalized' value to go to zero.  Rounding the result fixes this, and
is probably more desireable anyway.

(cherry picked from commit 42bae47be8794eac2dadff3b4fd1a7fa3c547b82)
Idle Timer: don't start the timer if it is 0 (disabled)

This fixes a bug with the frontend going to 100% CPU whenever the idle timer
was resumed.

(cherry picked from commit c61aee39349ced99f32586872a551d9445c226cc)
Idle Timer: fix the last cherry-pick
ImageLoadThread: don't treat all gifs as being animated

If a gif only has one image then fall back to loading it as a normal image.
This fixes the bad flicker of some gif images especially remote ones in button
lists.

Fixes #11883.

(cherry picked from commit bd0b51f1676f8e8b62e4b552bd48ccecb5378d9f)
Revert "Player: Improve low bit rate / high latency stream playback"

This reverts commit f307a3d5e60b0054e1833127d417c6acfada3213.

Cause stutter until channel changes
Merge branch 'fixes/0.27' into devel/027candidates