sourceLookupDirectory is out of date

When using the Eclipse interactive debugger occasionally tracing code and breakpoints will result in the source not being found. This is because over time the various .launch (and mainly opendaylight/distribution/opendaylight/opendaylight-application.launch) files have become out of date.

At the very least, we should update them to make them current, but in the long run, something should help maintain this opaque string.

The actual line starts something like:
<stringAttribute key="org.eclipse.debug.core.source_locator_memento"