FakeFilterMapper: EnumMatchingFilters was always returning E_NOTIMPL.

A "return" statement was missing.
FakeFilterMapper: Various cosmetics.

Make sure that static member variables are easy to spot using the "s_" prefix.
Updated LAV Filters to 0.59.1-5-f74c5c2 (custom build based on stable version 0.59.1).
Update Changelog.txt
Get rid of comma in delete statements.
Be consistent with NVIDIA name.
Installer: Use Inno Setup Preprocessor's `AddBackslash` function.

Also bump the required Inno Setup version in VSFilter's installer.
build.bat: Add error checking when extracting the DX cab files.

Also allow `EXPAND` to show info when doing its job.
Indentation improvements and trim trailing spaces from comments.
No need to nullify a member variable in a destructor.
FakeFilterMapper hooks: Document the check for "negative" registry key handles.
FakeFilterMapper: Don't call Init() unless we are sure it's safe to do so.
Improve the Get(Cur)DispMode and SetDispMode functions.

Fixes CID #966222.
Display more descriptive window title in capture mode.

Use new title also for Skype Now Playing status.

Based on Underground78 suggestions.
DVB: Add event name to the window title when available.

- Change logic when ParseEIT fails.
- Change UpdatePSI to not search for channel again.
BD: Open index.bdmv directly by internal LAV and let it select playlist.
Fix DXVA status for some decoders after 4a79186.

Checking status only once is not reliable.
Even LAV Video Decoder can disable HW decoding on fly except DXVA Native mode.
Show HW decoder name in status bar.