Added a simple check for stray tracked refs.

The idea is to make sure the main thread is getting through the VM init
process with an empty tracked references table.  If we find any, we
print a warning and dump the table, but continue on anyway.

My test was a trivial dvmMalloc(), which turned up a flaw in the ref
table dump code: it didn't deal with "raw" dvmMalloc sections.  So
that's fixed as well.