This directory holds third party libraries.

If you got MuPDF from a source release tarball, these libraries have been
stripped down for size and do not include test files and other auxiliary data.
If you want the full versions you should clone from git!

If you got MuPDF from a git checkout, these are git submodules.

To set up the third party modules for building from git:

	$ git submodule init
	$ git submodule update

Then after each pull (to make sure they're up to date):

	$ git submodule update

If the directories are empty or missing, the makefile based build will try to
use system libraries instead.

Do NOT edit files in the submodule checkouts unless you know what you're doing.