Add support for Mac OS X sparse images (.sparseimage) to HFSExplorer.

This depends on functionality from DMGExtractor. We update
hfsx_dmglib.jar to include the following commit (and its ancestors):
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Add support for Mac OS X sparse image files (.sparseimage).

The sparseimage file format was used before the introduction of sparse
bundles. It is a relatively simple format with a 4 KiB header containing
a block map from physical blocks to virtual blocks. When space runs out
in the header, an extension header (also 4 KiB) is written to the end of
the file before allocating the next block, appending its contents after
the extension header, and so on.

When encrypted, the sparseimage format is enclosed in a
CEncryptedEncoding wrapper (not the other way around, since that would
make it very difficult to reclaim space in the sparse image).
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UnHFS.java: Add support for Mac OS X sparse bundles.
UnHFS.java: Print version number and copyright notices in help message.
UnHFS.java: Accept password from stdin.

Specifying the password on the command line is insecure and could lead
to the password being logged. Some would probably prefer piping it to
unhfs instead.