Pycups

- remove the install_requires from setup.py

- removed shebang from example/cupstree.py
- ignore driverless utilities for postscriptdriver tags creation (Fedora bug 1873385)
- remove epydoc from Makefile (27)
- fix invalid delete of pointer (11)
- Makefile uses wrong Python (32)
- define PY_SSIZE_T_CLEAN in cupsipp.h - fixes traceback during IPPRequest.writeIO
with Python 3.10
- fix the test.py when there is no printer installed (46)
- Use PyObject_Call() instead of deprecated PyEval

- attempts to fix installation in PyPi

* pypi required .tar.gz
* cups.require couldn't handle version bigger than 1

* dropped macros for older CUPS < 2.0.0
* dropped Python 2 support and its related macros
* update license headers
* thread did not hold GIL when called Py_XDECREF() from destroy_TLS(), causing SIGSEGV(Fedora bug 1816107)
* fixed several compiler warnings
* fix silent error on Connection.printFiles() (patch by Wilbert Berendsen)

* fix Connection_writeRequestData with binary data (https://github.com/zdohnal/pycups/pull/1)
* misspelling (patch by Edward Betts)
* fixed print function in example/cupstree.py (patch by Jiri Popelka)