Use commit message best practices for Mylyn Commit template

We should use a template for Mylyn commit messages that matches with our
guidelines for commit messages.

http://wiki.eclipse.org/EGit/Contributor_Guide#Commit_message_guidelines

Bug: 337401
Change-Id: I05812abf0eb0651d22c439142640f173fc2f2ba0
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
38 files changed