492212: [release] release Mylyn 3.20 (update version)

Change-Id: Ia1864f1487c04f5f42770dc4fc1677e16035d638
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=492212
Signed-off-by: Frank Becker <eclipse@frank-becker.de>
30 files changed