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

Change-Id: I4d2a8244a4926b78d113c4a6e6e95ca3f41f614f
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=492212
Signed-off-by: Frank Becker <eclipse@frank-becker.de>
71 files changed