Fix drag-and-drop from some applications.

Drag-and-dropping a downloaded file from Chrome failed for example.

This commit fixes #3036.
Update translations from Transifex:

 - Basque
 - British English
 - Catalan
 - Chinese (simplified)
 - Croatian
 - French
 - Galician
 - German
 - Greek
 - Italian
 - Japanese
 - Korean
 - Polish
 - Portuguese (Brazil)
 - Slovak
 - Spanish
 - Turkish
 - Vietnamese
Don't update the last window position when the option is disabled.

Avoid always modifying the settings for those who sync them.

Fixes #4377.
ISR: Render text subtitles relative to the video frame when in doubt.
Don't force any background color for the Shockwave graph.

This commit fixes #1747.
Why "C:\tmp.srt"?
Fix some CPPCheck warnings or mark them as intentional.
WebUI: Inform the web interface that no audio stream is available.
WebUI: Make use of new [hasaudio] info.
What the hell was intended here?!

Trying to make some sense of that code. Without much luck so far...
Fix: x86 and x64 versions conflicted over file associations.

4f465cf8b81f1da800b1bfc57cc48e317d24fbb5 was incomplete for Vista+.

This commit fixes #4064.
Auto mode for relative to.