Revert "Ensure cancelling a download is done in the same thread it started; take #2"

This reverts commit 229a4267480a59b9a0de02e2d5ad4c9a971b7c9c.
Revert "Revert "Fix MythDownloadManger after 997f7aa10. It was possible for queue and cancel requests to be handled out of order resulting in newly queued downloads being cancelled almost immediately. We avoid this by removing any cancelled downloads  from the download queue to a new cancellation queue, then we clean up the cancelled downloads later without affecting new additions.""

This reverts commit eb3a3382a21c71fd0d1c9ff57aa64480ad03b36a.
Revert "Revert "Prevent multiple instances of the same DownloadInfo pointer being added to the cancellation queue""

This reverts commit e715acc3fbf72c54cea97df27ef7661221fb3dab.
Use a queue to cancel downloads.
cancelDownload can be blocking or not.
Add API to cancel a list of urls.
Hopefully prevent another racing conditions seen with HLS recorder when changing channels quickly.

Fixes #11663
Bump API
Use new MythDownloadManager::cancelDownload(QStringList) API

So we only need to wait once for all download to be cancelled.
Don't block when cancelling a URL.
Typos

Refs #11741

Signed-off-by: Nicolas Riendeau <nriendeau@mythtv.org>
update for 1.2.2

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Jean-Yves Avenard <jyavenard@mythtv.org>
Revert "pnm: remove nonsense code"

Breaks decoding pgms with 255 < maxval < 65535.

Found-by: Carl Eugen Hoyos <cehoyos@ag.or.at>.

This reverts commit a0348d0966a81a66f3a1bf061576b24d5296b933.
(cherry picked from commit 768e40b451a459fefaceed6b1b3d6e70c93596ac)

Signed-off-by: Jean-Yves Avenard <jyavenard@mythtv.org>
avcodec/kmvc: fix MV checks

Fixes Ticket2813
Fixes regression since 70b5583

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 3cd8aaa2b2e78faf039691e1c31ff4f8d94e3bc6)
Signed-off-by: Jean-Yves Avenard <jyavenard@mythtv.org>
FFmpeg re-sync with f9c87262
Merge branch 'master' of code.mythtv.org:mythtv
Improve the wording of two sentences.

Thanks goes to Stuart Morgan
Updated full GB English translation from Nick Morrott

Refs #11742

Signed-off-by: Nicolas Riendeau <nriendeau@mythtv.org>