twisted: Rename package, fix errors

This renames the Python 2 twisted package to python-twisted, and updates
dependents (i.e. obfsproxy) to reference the updated name.

This also fixes conflicts between the Python 2 and 3 packages. Twisted
installs some scripts to /usr/bin, and previously scripts for both
packages used the same names. This adds a "3" suffix to scripts
installed by python3-twisted.

This also adds python[3]-setuptools as a dependency, as the scripts
installed to /usr/bin depend on pkg_resources (part of setuptools).

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/python/python-twisted/patches/002-omit-tests.patch

@@ -0,0 +1,37 @@
+--- a/src/twisted/python/_setup.py
++++ b/src/twisted/python/_setup.py
+@@ -169,11 +169,6 @@ class ConditionalExtension(Extension, object):
+ 
+ # The C extensions used for Twisted.
+ _EXTENSIONS = [
+-    ConditionalExtension(
+-        "twisted.test.raiser",
+-        sources=["src/twisted/test/raiser.c"],
+-        condition=lambda _: _isCPython),
+-
+     ConditionalExtension(
+         "twisted.internet.iocpreactor.iocpsupport",
+         sources=[
+@@ -238,12 +233,11 @@ def getSetupArgs(extensions=_EXTENSIONS):
+         "incremental >= 16.10.1",
+         "Automat >= 0.3.0",
+         "hyperlink >= 17.1.1",
+-        "PyHamcrest >= 1.9.0",
+         "attrs >= 17.4.0",
+     ]
+ 
+     arguments.update(dict(
+-        packages=find_packages("src"),
++        packages=find_packages("src", exclude=["*.test", "*.test.*"]),
+         use_incremental=True,
+         setup_requires=["incremental >= 16.10.1"],
+         install_requires=requirements,
+@@ -253,7 +247,7 @@ def getSetupArgs(extensions=_EXTENSIONS):
+         cmdclass=command_classes,
+         include_package_data=True,
+         exclude_package_data={
+-            "": ["*.c", "*.h", "*.pxi", "*.pyx", "build.bat"],
++            "": ["*.c", "*.h", "*.pxi", "*.pyx", "build.bat", "test/*"],
+         },
+         zip_safe=False,
+         extras_require=_EXTRAS_REQUIRE,