Fix: Some subtitles could have been missing.

Depending on how the subtitle entries overlapped in time, some segments were forgotten when creating them on the fly which led to incomplete rendering.

This regression in ef0327fa92b6938f5ef70dea49fe2ecbbd86757b was made visible by fa670bfc0b1d4d620bfc0388e9fd41b6275e8d4f.
Subtitle renderer: Fix the Gaussian blur SSE2 filter for small subpicture.

The blur filter was applied twice on some part of the subpicture when the size was too small to use SSE2.

This commit fixes #3981.
Update translations from Transifex:

 - Armenian
 - Basque
 - Chinese (simplified)
 - French
 - German
 - Japanese
 - Portuguese (Brazil)
 - Swedish
 - Turkish
 - Ukrainian
Fix the DVD favorites: the position in the DVD was not restored.

After 1c3d80162511fe5ddbe36a7988e610cc2ee85a2c the DVD state was restored when the crash was still stopped so it had no effect.

Additionally if "Remember DVD position" is enabled and a DVD favorite has a position, the position from the favorite will be used instead of the remembered position.

This commit fixes #3988.
Fix loading of DVD favorites created with "Remember position" disabled.
Fullscreen option page: fix an assert.

EnumDisplayDevices returns false when reaching the last item.
Update translations from Transifex:

 - British English
 - German
 - Japanese
 - Malay
 - Polish
 - Slovak
 - Swedish
The "Debug Shaders" dialog icon was missing when a translation was used.

This commit fixes #3998.
Add a Galician translation.

The composition of the translation team can be found on Transifex: https://www.transifex.com/projects/p/mpc-hc/language/gl/members/.
Add a Vietnamese translation.

The composition of the translation team can be found on Transifex: https://www.transifex.com/projects/p/mpc-hc/language/vi/members/.