Update NEWS from dia-0-97 branch

dia-0.97.3: 2014-09-05

 * Fix double free with some SVG rendering (regression from Dia 0.97.2)
 * Fixes to cope better with updated versions of Dia's dependencies:
   - don't crash at start-up with ABI breaking GLib 2-36
   - don't assert in cairo 1.12 with invalid arc parameters
   - avoid kerning problems (character overlap) for all Pango versions
   - fix image files to be loadable by libpng16
 * Backport fixes for some seldom crashes and other annoyances, see:
   http://bugzilla.gnome.org/buglist.cgi?product=dia&target_milestone=0.97.3
 * Update translations for Brazilian Portuguese, German, Hungarian,
   Polish, Romanian, Serbian and Slovenian