Code cleanup

Applied format template.
Closed testing resources

Added tearDown methods to io/scif/io/utests/* that close each
IRandomAccess. These were remaining open during testing, causing memory
leaks.
Implemented ByteArrayHandle#close()

This method was not implemented, perhaps because the underlying byte
buffer did not have a corresponding close method. However, this was
causing a memory leak since the resources were never released.

Close now nulls the underlying buffer, which is sufficient to free its
memory.
Improved caching stability

In the MapDBCache:
* disabled WAL
* disabled asynchronous writing

This should eliminate potential OOM errors due to asynch writing. WAL
and compression changes should mitigate that somewhat.