WINTERMUTE: Lose "TODO: Add subtitles-support"

I guess we do have subtitles support now
WINTERMUTE: Lose unnecessary if() in VideoTheoraPlayer
WINTERMUTE: Don't bother inheriting BaseGame in SubtitleCard
WINTERMUTE: Remove useless default constructor from SubtitleCard.
WINTERMUTE: Const'fy members of class SubtitleCard
WINTERMUTE: Introduce BaseGame->expandStringByStringTable(&Common::String)
WINTERMUTE: Use BaseGame->expandStringByStringTable(&Common::String) in SubtitleCard
WINTERMUTE: s/delete array/delete[] array/
WINTERMUTE: Use int32 for _lastSample in VideoSubtitler

We are thus making room for the sentinel == -1
WINTERMUTE: Initialize tokenSomething vars in VideoSubtitler

MSVC complains otherwise.
WINTERMUTE: Turn _subtitles into Common::Array<SubtitleCard> in VideoSubtitler

This necessarily loses const in SubtitleCard's attributes
WINTERMUTE: new char[str.size()+1] in BaseStringTable::expand

This makes room for the EOL char.