#23 Add fonts to SRT and W3C Timed Text

[Simon]

This patch adds two outputs to the teletext subtitles:
- SRTC - Like SRT only with font tags for colours
- W3C - W3C Timed Text format including colours

I hope to add GPAC Timed Text soon but it is a bit more complicated.

[Simon]

The latest patch adds GPAC support to W3C and SRTC.

It also adds a dependency for org.apache.commons.lang.StringEscapeUtils to escape for the XML in GPAC.

[Simon]

Adds SRTC, W3C and GPAC teletext output formats. Typo fix.