libxml-2.0.vapi: improve XmlError, provide get_last_error method to xmlParserCtxt, define ErrorDomain enum
Attr.vala: rearrange description
gxml/*.vala: update docs, markup special values, type links, and add memory management guidance
CharacterData,Implementation,Node.vala: change protected functions to internal, so they aren't exposed in C
glib-2.0.vapi: get rid of trailing whitespace
Error.vala: Add GXml.Error errordomain, for actual exception handling unlike DomExceptions
Makefile.am: compile Error.vala
Document.vala: add GXml.Error to Document.from_path, use Xml.ParserCtxt.read_file instead of Xml.Parser.parse_file, for error-handling
Document.vala: add error handling to IO operations
README: add guidance for documentation
gxml/*.vala: add a linebreak between Version and URL; sadly only works in Valadoc HTML, not gtkdoc devhelp
gxml/*.vala: fix examples in comments regarding line breaking
Document.vala: improve documentation significantly, describe parametres, link more types, and indicate memory management on return types
Element.vala: improve documentation by removing unnecessary periods, and inheriting more docs
Error.vala: add WRITER errorcode
gxml/*.vala: remove unnecessary periods
Document.vala: add more error reporting
DocumentTest.vala: test error handling for doc save and load