We no longer need to merge pages this way. Much of the functionality
was there to implement page splitting without hitting ulimit which
will be fixed in qpdf > 8.0.2. The tests were expensive to run.
Also remove pytest-timeout since it breaks the Linux build.
Source files to GPL3
Exceptions:
-tests/spoof/* to MIT
-hocrtransform.py
-_unicodefun.py
Test resources to CC BY-SA 4.0 except when otherwise noted.
Add GPL license.
