Update LAV Filters to 0.59.1-107-2d6cc0e (custom build based on 0.59.1-102-61c89de).

Important changes:
 - LAV Splitter: The current/average bitrate is now shown in the Information panel (fixes #3540).
 - LAV Video: Some decoding regressions have been fixed.
 - Update libbluray to 0.5.0.
DVB: Fix channel change when the graph was previously stopped.
Fix: The screen stayed black when restarting a file.

This commit fixes ticket #3908.
Correct some typos.

This fixes #3877.
CTextFile: Add a buffer for read operations.
SimpleTextSubtitle: Optimize Add function to improve the parsing speed.
SimpleTextSubtitle: Add missing break statement.
SimpleTextSubtitle: GetInt: Avoid temporary CString construction.
STS: Fix CreateSegments not to create empty segments.
STS::Add: Some segments were forgotten when inserting.
Sub renderer: Avoid rendering many times the exact same subtitle.
Rasterizer: Constify some stuff.
RTS: ScanConvert shouldn't need a __try/__except.

This reverts bd96d9168129cbab728094c5b5773486fb291635.

Catching blindly all exceptions and silencing them is a bad idea. Also I couldn't reproduce the problem with LAV Filters and the latest version of the old MPC MP4/MOV Splitter.
Subtitle renderer: Add a cache to avoid regenerating the same outlines.

This commit generally speeds up the rendering process by a factor 2 to 4.
Subtitle renderer: Add a cache to avoid regenerating the same overlay.

This commit improves the rendering process speed up to a factor 2 for complex subtitles.
Subtitle renderer: faster Gaussian blur filter.

About twice as fast as the old filter in general without any output change.
Subtitle renderer: Use two different planes for the subtitle body and its border.
Subtitle renderer: Use short integers for the Gaussian blur filter kernel.

No output change, will be useful for future work.
Subtitle renderer: SSE2 Gaussian Blur filter.
Subtitle renderer: Gaussian blur filter: Use SSE2 aligned load whenever possible.