Only jump back in a menu to the nearest previous block with subpictures if a seek operation is already in progress.

This should prevent infinite loops on some discs (e.g. Independence Day) where the menu highlight packets are somehow not processed before the navigation data indicates that buttons must be shown.
(cherry picked from commit e37383db1f55ad21f200903c18f9750753e05f00)
Prevent MythWelcome blocking input devices when calling mythshutdown to avoid resetting the idle timer (see [cac1413]) when trying to determine whether the backend is idle, thereby preventing shutdown.
(cherry picked from commit 1431eecd20c020b9c0ad826993015bc8957e82d6)
Reduce logging level for GetKeyframePositions and GetKeyframeDurations.
(cherry picked from commit 3c90e595d998e563c7a97a39f9541c157762755e)
Fix ordering of Artwork in selection dialogs. Best matches should now appear first, not last.
(cherry picked from commit d95a237d6cf7e79b4b5f807600fd635f37337e2f)
Use category type as a hint in the Schedule Editor Metadata/Artwork searches
Fix python bindings to store updates to video markup data.
(cherry picked from commit 13ae25f5c86bd29a4e854cd5d438436f26d7345e)
Fix segfault in Schedule Editor. Not all recording rules are associated with a program and this pointer therefore needs to be checked first
Icon Downloader: Fix 'Re-scan for missing' to check the Channel Icon storage group
(cherry picked from commit 19f6b618045e9ac9bb7657e90f915e09dc63ba14)
Make the check for an existing icon more robust.
(cherry picked from commit 8b1d8159331e85569d78f5637df49366e5198f40)
Fix display for progress dialog in Icon Importer
(cherry picked from commit 243420f6c1e043530fbe919ec85ae9f41af56323)
Metadata Lookup: We want to use the first (best) result, not the last.
Icon Downloader: Check that the existing icon is actually a valid image.
Merge branch 'fixes/0.27' into stable/0.27