grc: adding a page that captures and stores some XML parsing errors
grc: include display of suspect source lines in xml parser warnings
grc: don't show block tree xml parsing as block dtd errors
grc: xml errors dialog fixes and refactoring
grc: detect block (category) tree files by name (not trail&error)
grc: Show message for parser errors
grc: Renaming flowgraph errors menu item
grc: ParseDialog improvements