Replace unmaintained cmdln.py with a custom code

Cmdln.py is unmaintained for years and uses deprecated optparse.
Let's replace it with a simpler custom code. Also remove code
that generates man page, we'll replace it with a 3rd party tool.

setup.py

@@ -1,69 +1,11 @@
 #!/usr/bin/env python3
 
 
-import distutils.core
-import gzip
-import os
 import setuptools
-from distutils.command import build, install_data
 
-import osc.commandline
 import osc.core
 
 
-class build_osc(build.build):
-    """
-    Custom build command which generates man page.
-    """
-
-    def build_man_page(self):
-        """
-        """
-        try:
-            os.makedirs(self.build_base)
-        except OSError:
-            pass
-        man_path = os.path.join(self.build_base, 'osc.1.gz')
-        distutils.log.info('generating %s' % man_path)
-        outfile = gzip.open(man_path, 'wt')
-        osccli = osc.commandline.Osc(stdout=outfile)
-        # FIXME: we cannot call the main method because osc expects an ~/.oscrc
-        # file (this would break builds in environments like the obs)
-        # osccli.main(argv = ['osc','man'])
-        osccli.optparser = osccli.get_optparser()
-        osccli.do_man(None)
-        outfile.close()
-
-    def run(self):
-        super().run()
-        self.build_man_page()
-
-
-# take a potential build-base option into account (for instance, if osc is
-# build and installed like this:
-# python setup.py build --build-base=<dir> ... install ...)
-class install_data(install_data.install_data):
-    def initialize_options(self):
-        super().initialize_options()
-        self.built_data = None
-
-    def finalize_options(self):
-        super().finalize_options()
-        self.set_undefined_options('build', ('build_base', 'built_data'))
-        data_files = []
-        for f in self.data_files:
-            # f is either a str or a (dir, files) pair
-            # (see distutils.command.install_data.install_data.run)
-            if isinstance(f, str):
-                data_files.append(os.path.join(self.built_data, f))
-            else:
-                data_files.append((f[0], [os.path.join(self.built_data, i) for i in f[1]]))
-        self.data_files = data_files
-
-
-data_files = []
-data_files.append((os.path.join('share', 'man', 'man1'), ['osc.1.gz']))
-
 with open("README.md") as fh:
     lines = fh.readlines()
     while lines:
@@ -77,8 +19,6 @@ with open("README.md") as fh:
     long_description = "".join(lines)
 
 cmdclass = {
-    'build': build_osc,
-    'install_data': install_data
 }
 
 # keep build deps minimal and be tolerant to missing sphinx
@@ -104,7 +44,6 @@ setuptools.setup(
     url='http://en.opensuse.org/openSUSE:OSC',
     download_url='https://github.com/openSUSE/osc',
     packages=['osc', 'osc.util'],
-    data_files=data_files,
     install_requires=['cryptography', 'urllib3'],
     extras_require={
        'RPM signature verification': ['rpm'],