[KARAF-2171] Add general sonatype snapshot repositories

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1444496 13f79535-47bb-0310-9956-ffa450edef68
[KARAF-2176] Upgrade to Pax URL 1.5.1

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1444581 13f79535-47bb-0310-9956-ffa450edef68
[KARAF-2114] Cleanup "old" local-repo references

git-svn-id: https://svn.apache.org/repos/asf/karaf/trunk@1444680 13f79535-47bb-0310-9956-ffa450edef68