Fixes #10519. Adds workaround for cx8800 driver.

This card reports V4L2_CAP_STREAMING but doesn't support streaming. The bug has been reported on the #linuxtv IRC channel.
Fix settings overrides. I accidentally broke these when changing the DB connection code.
Move some database logging left over from the DB connections re-write to VB_DATABASE. This makes for less log clutter to wade through when debugging issues or reviewing logs with the new log viewer.
MPEGRecorder: Close chanfd if we fail to initialize device. One of the cases wasn't handled.
MPEGRecorder: _error is a QString not a bool, set it appropriately.
Fixes #10501. Adapt to new return ioctl return value in Linux 3.1.

Thanks to Anthony Messina for discovering the issue and the original patch.

A different change was used only because #10501 will require a single point of exit from the functions affected.
Fix unhandled keypresses causing the mythmusic volume display timer to stay on screen for longer than it normally would. If something has changed then we do want to keep it on-screen, but if the user was trying to control something on the screen beneath the popup we shouldn't keep swallowing keypresses.
Refs #9830. Fix some debugging output problems observed in logs on ticket.
Refs #10518. Fix CetonStreamHandler error logging.
Fixes #10518. Fix CetonStreamHandler deadlock.

This wasn't a QMutex deadlock like most of them are, this was caused by variable aliasing preventing the _error signal from CetonStreamHandler::run() from being communicated to StreamHandler::Start().

Thanks to Steven Adeff for reporting this and providing a good backtrace.
Extend the overrides fix in [973df175] to GetSettingOnHost() and GetSettings().

Thanks go out to Jean-Yves Avenard for discovering the bug and Raymond Wagner for pin-pointing it in the code.
Only attempt language fallthrough if polling function is supplied.

This tweaks the Poller() class to accept null values if applied to a
datapoint that has no specified function to query relevant data from
TheMovieDb. This corrects an issue where language specified for images
would not get populated, and then return an error when retrieved.
Updated Greek MythFrontend, MythArchive, MythBrowser, MythGallery,
MythGame, MythMusic, MythNetvision, MythWeather and MythZoneMinder
translation from Yianni Vidalis.

(MythNews contained no new translations.)

Thank you Yianni!

Closes #10525

Signed-off-by: Nicolas Riendeau <nriendeau@mythtv.org>
Correct newline escape.
Split cache engines into own files. Add msvcrt locking for file engine.

This splits each of the current cache engines into separate files for
easier management, and reworks organization a bit to correct dependency
issues. This also adds a secondary file locking mechanism for Windows
where flock is not available.
Merge commit '4663490f8fa99dd5869aff595f56873175e47826'
Rollup DB changes to 1299 for initial database.

This updates the InitializeMythSchema() function to create a new
database at DB schema version 1299 (current schema version) so new users
will not be asked to allow a DB upgrade.
Updated French language MythFrontend and all plugins translations
from the French Language Translation Team.

Thank you!
Updated Hong Kong Chinese MythFrontend and MythArchive translation
from Walter Cheuk

Thank you Walter!

Closes #10527

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