Merge branch 'release-0.4.5'
Added Exporter::showPageIds(), Exporter::hidePageIds(), Exporter::getShowPageIds().
Fixed bug that wouldn't export FlatText that had \r and \n in cell.
Added MarkdownTableExporter.
Version bumped from 0.4.5 to 0.4.6
Merge branch 'release-0.4.6'