mupdf-legacy (older version of mupdf)

mupdf is a lightweight PDF, CBZ, and XPS viewer and toolkit. mupdf-legacy
is an older version of mupdf that gets installed to /opt/mupdf-legacy,
for use with zathura-pdf-mupdf and fbpdf2.

Notes:

1. Since this gets installed to /opt, the binaries (mupdf-x11, etc) will
   not be in your $PATH. This is by design: for standalone use, it's
   better to install the regular mupdf package, which is the latest
   version.

2. JavaScript support and shared libraries are disabled. Again, you want
   the regular mupdf package for these.

3. Any build that links with this needs to be modified so it looks for
   headers and libraries in /opt/mupdf-legacy. See zathura-pdf-mupdf for
   an example.