Drop unused code from the old internal filters era.
unrar.vcxproj: remove obsolete _ProjectFileVersion property.
Run astyle.
Readme.md: Add Coverity badge.
Remove VS2012 support.

From the next LAV Filters update, VS2013 is required to build.

Closes PR #122.
Update LAV Filters to 0.59.1-93-4cd23f1 (custom build based on 0.59.1-88-2b2c763).

Important changes:
 - LAV Splitter: Fix a crash when opening MKV files with big attachments (fixes #3862).
 - LAV Video: DXVA VC1/WMV3 decoding now works on Intel cards (fixes #3849).
Installer: Use the same short names than the main exe for the translations.
Installer: Make the lang IDs consistent with the main executable.
Installer: Put the translated custom messages in a separated file.
Translation script: Use the lang short name instead of the full filename.

The filename depends only of the language short name and we will need the short name later anyway.
Translation script: Split the main script into two files.

Separate functions directly related to PO(T) files from those directly related to RC files.
Translation scripts: Add support for the installer strings.
Transifex client config: Add the new resource for the installer strings.
Fix a possible dead lock when opening a file when one is already playing.

Easily reproducible with madVR.

Ticket #3865.