setup.py: add a python setuptools package.

To build a package suitable for python's pip tool:
	python setup.py sdist

To install a pre-built package from pypi:
	pip install redo-tools

setup.py

@@ -0,0 +1,59 @@
+import os, setuptools, subprocess
+
+# Construct the redo input files, including redo.version, if we're
+# starting from the original redo source dir.  If we're running
+# from the python pip package, the files already exist, so we
+# skip this step.
+mydir = os.path.dirname(__file__)
+script = os.path.join(mydir, 'do')
+verfile = os.path.join(mydir, 'redo/version/_version.py')
+if os.path.exists(script) and not os.path.exists(verfile):
+    subprocess.check_call([script])
+
+
+import redo.version
+
+
+def read(fname):
+    return open(os.path.join(mydir, fname)).read()
+
+    
+# FIXME: we probably need to build redo/sh on the target system, somehow.
+setuptools.setup(
+    name = 'redo-tools',
+    version = redo.version.TAG.replace('-', '+', 1),
+    python_requires='>=2.7, <3.0',
+    author = 'Avery Pennarun',
+    author_email = 'apenwarr@gmail.com',
+    description = ('djb redo: a recursive, general purpose build system.'),
+    long_description=read('README.md'),
+    long_description_content_type='text/markdown',
+    license = 'Apache',
+    keywords = 'redo redo-ifchange make dependencies build system compiler',
+    url = 'https://github.com/apenwarr/redo',
+    packages = setuptools.find_packages(),
+    classifiers = [
+        'Development Status :: 4 - Beta',
+        'Environment :: Console',
+        'Topic :: Utilities',
+        'License :: OSI Approved :: Apache Software License',
+        'Operating System :: POSIX',
+        'Topic :: Software Development :: Build Tools',
+        'Topic :: Utilities',
+    ],
+    entry_points = {
+        'console_scripts': [
+            'redo=redo.cmd_redo:main',
+            'redo-always=redo.cmd_always:main',
+            'redo-ifchange=redo.cmd_ifchange:main',
+            'redo-ifcreate=redo.cmd_ifcreate:main',
+            'redo-log=redo.cmd_log:main',
+            'redo-ood=redo.cmd_ood:main',
+            'redo-sources=redo.cmd_sources:main',
+            'redo-stamp=redo.cmd_stamp:main',
+            'redo-targets=redo.cmd_targets:main',
+            'redo-unlocked=redo.cmd_unlocked:main',
+            'redo-whichdo=redo.cmd_whichdo:main',
+        ],
+    },
+)