CodeSnip Old Code (SVN)

Tweaked and corrected commenting.

* Renamed UTextStreamReader unit as UStringReader and TTextStreamReader class as TStringReader. Changed TStringReader to read its data from a string instead of a stream.
* Updated using Hiliter.UPasLexer unit to use revised unit and class names.
* Updated chain of Hiliter classes that use Hiliter.UPasLexer to pass source code as a string instead of a stream. When streams were used they had to contain Unicode text, so it is safer and easier just to use strings instead.