Changes

580782: Remove obsolete update*.sh version scripts

These shell scripts were used for updating the pom, feature and manifest
files in the epub and wikitext directories. The new build process
makes these scripts obsolete.

Update the corresponding release steps in the root README file.

Change-Id: I09aea9bf4da313b2baa42bce510273b31e35bef6
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=580782

580782: SCM plugin connects to mylyn docs git over SSH

Configure the maven SCM plugin to use SSH for connecting to the mylyn
docs git repository. Connecting via https is unsupported within the
context of the jenkins job. SSH credentials are already specified
in the Jenkins configuration.

The proper SSH-based git url is defined already in the POM's
SCM.developerConnection property so reference that from the scm plugin
configuration.

Change-Id: I0e3de630d24eddf1c7f95be2331283a9e164ff7d
Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=580782