Added ability to just randomly create metadata without linking them in
to the current event chain.  Added some utility methods in XTraceContext
that pre-generate some metadata to pass to a child process, that the
child process then later uses to log the end of the process.  That
facilitates the child process linking back in to the parent process (if
necessary).
Merge branch 'master' of https://github.com/brownsys/X-Trace.git

Conflicts:
	src/java/src/main/java/edu/berkeley/xtrace/XTraceContext.java