Fix export of non-ODF interpolation types to ODF.

2014-05-19  Andreas J. Guelzow <aguelzow@pyrshep.ca>

	* openoffice-write.c (od_style_prop_chart): use gnm:interpolation rather
	than using an invalid attirbute value with chart:interpolation
	* openoffice-read.c (od_style_prop_chart): handle gnm:interpolation
Fix export of titles and subtitles to ODF. [part of #730397]

2014-05-19  Andreas J. Guelzow <aguelzow@pyrshep.ca>

	* openoffice-write.c (odf_write_title): do not write table:cell-address