Bug 416514 Remove references to eclipse-signing-maven-plugin

https://bugs.eclipse.org/bugs/show_bug.cgi?id=416514
Remove (outdated) references to project dash
eclipse-signing-maven-plugin from pom.xml's
Update p2 URLs to Kepler SR1 RC3
Merge remote-tracking branch 'rap/streams/2.1-maintenance' into patches/2.1/bsiPatches