Add MANIFEST.in to get LICENSE.txt in the package.

This also adds package_data and friends to the setup.py. Not that they
seemed to do anything...

Author: ionrock

MANIFEST.in

@@ -0,0 +1 @@
+include LICENSE.txt

setup.py

@@ -12,6 +12,9 @@
     url='https://github.com/ionrock/cachecontrol',
     keywords='requests http caching web',
     packages=setuptools.find_packages(),
+    package_data={'': ['LICENSE.txt']},
+    package_dir={'cachecontrol': 'cachecontrol'},
+    include_package_data=True,
     description='httplib2 caching for requests',
     long_description=long_description,
     install_requires=[