DVB: Add signal statistic to the status bar.

This commit fixes #899.
Move strings used in the status bar to resources.
Remove unused IDS_SCREENSHOT_ERROR_MADVR string from resources.
Disable some menus when it make sense to do so.
DVB: Disable pause for capture mode to avoid accidental playback stop.
We don't support time shifting yet.

This commit fixes #890.
Updated Polish translation.
apply astyle
cosmetics
Cosmetics: Add missing units for BDA signal statistic.
Updated German translation.

This commit fixes #2909.
DVB: Fix default audio track selection when its type is different than
first audio track.

This commit fixes ticket #2396
DVB: Remember audio and subtitle track selection.