This update for MozillaThunderbird fixes the following issues:

- update to Thunderbird 45.3.0 (boo#991809)
  * Disposition-Notification-To could not be used in
    mail.compose.other.header
  * "edit as new message" on a received message pre-filled the sender
    as the composing identity.
  * Certain messages caused corruption of the drafts summary database.
  security fixes:
  * MFSA 2016-62/CVE-2016-2836
    Miscellaneous memory safety hazards
  * MFSA 2016-63/CVE-2016-2830 (bmo#1255270)
    Favicon network connection can persist when page is closed
  * MFSA 2016-64/CVE-2016-2838 (bmo#1279814)
    Buffer overflow rendering SVG with bidirectional content
  * MFSA 2016-65/CVE-2016-2839 (bmo#1275339)
    Cairo rendering crash due to memory allocation issue with FFmpeg 0.10
  * MFSA 2016-67/CVE-2016-5252 (bmo#1268854)
    Stack underflow during 2D graphics rendering
  * MFSA 2016-70/CVE-2016-5254 (bmo#1266963)
    Use-after-free when using alt key and toplevel menus
  * MFSA 2016-72/CVE-2016-5258 (bmo#1279146)
    Use-after-free in DTLS during WebRTC session shutdown
  * MFSA 2016-73/CVE-2016-5259 (bmo#1282992)
    Use-after-free in service workers with nested sync events
  * MFSA 2016-76/CVE-2016-5262 (bmo#1277475)
    Scripts on marquee tag can execute in sandboxed iframes
  * MFSA 2016-77/CVE-2016-2837 (bmo#1274637)
    Buffer overflow in ClearKey Content Decryption Module (CDM)
    during video playback
  * MFSA 2016-78/CVE-2016-5263 (bmo#1276897)
    Type confusion in display transformation
  * MFSA 2016-79/CVE-2016-5264 (bmo#1286183)
    Use-after-free when applying SVG effects
  * MFSA 2016-80/CVE-2016-5265 (bmo#1278013)
    Same-origin policy violation using local HTML file and saved shortcut file

- Fix for possible buffer overrun (boo#990856)
  CVE-2016-6354 (bmo#1292534)
  [mozilla-flex_buffer_overrun.patch]

- add a screenshot to appdata.xml