Controls whether text is highlighted in the buffer. If setting is true,
the text will be highlighted according to the patterns installed in the
buffer (either set with set_language() or by adding individual
GTK2.SourceTag tags to the buffer's tag table). Otherwise, any current
highlighted text will be restored to the default buffer style.
Tags not of GTK2.SourceTag type will not be removed by this option, and
normal GTK2.TextTag priority settings apply when highlighting is enabled.
If not using a GTK2.SourceLanguage for setting the highlighting patterns in
the buffer, it is recommended for performance reasons that you add all the
GTK2.SourceTag tags with highlighting disabled and enable it when finished.
GTK2.SourceBuffer()->set_escape_char()