Update toolbar selection in dockzone calculation

Fixes #3804
build.bat: Add support for MPCTestAPI
Update coverity.bat.

Add MPCIconlib and MPCTestAPI.
sign.bat: Retry when signing fails.
Show error message when toolset call fails.
Update Unrar to 5.0.0.14.
Ensure we won't leak memory even in case of error.

CID 1134286 and 1134287.
CRenderedHdmvSubtitle: Remove an unused variable.

CID 1134288.
Update LAV Filters to 0.59.1-54-09ba2cf (custom build based on 0.59.1-49-b72fb1a)

Important change: Update libraries (ffmpeg, libspeex, Opus, opencore-amr).

Also fixes #3785.