Write invisible characters in ODF number style export. [#725852]

2014-03-06 Andreas J. Guelzow <aguelzow@pyrshep.ca>

	* goffice/utils/go-format.c (go_format_output_number_to_odf): write
	invisible characters; add argument
	(go_format_output_to_odf): adjust call to go_format_output_number_to_odf