Revert of the revert of the python package with version information

This reverts commit bee8f16dbb.

docs/release.rst

@@ -1,11 +1,12 @@
 To release a new version of pybind11:
 
 - Update version macros in `include/pybind11/common.h`
-- Update version in `setup.py`
+- Update `pybind11/_version.py` (set release version, remove 'dev')
 - `git add` and `git commit`.
 - `python setup.py sdist upload`.
 - `python setup.py bdist_wheel upload`.
 - `git tag -a X.X -m 'Release tag comment'`.
+- Update `_version.py` (add 'dev' and increment minor).
 - `git add` and `git commit`. `git push`. `git push --tags`.
 
 The remote for the last `git push --tags` should be the main repository for

pybind11/__init__.py

@@ -0,0 +1 @@
+from ._version import version_info, __version__

pybind11/_version.py

@@ -0,0 +1,2 @@
+version_info = (1, 3, 'dev0')
+__version__ = '.'.join(map(str, version_info))

setup.py

@@ -3,8 +3,7 @@
 # Setup script for PyPI; use CMakeFile.txt to build the example application
 
 from setuptools import setup
-
-__version__ = '1.3'
+from pybind11 import __version__
 
 setup(
     name='pybind11',
@@ -14,7 +13,7 @@ setup(
     author_email='wenzel@inf.ethz.ch',
     url='https://github.com/wjakob/pybind11',
     download_url='https://github.com/wjakob/pybind11/tarball/v' + __version__,
-    packages=[],
+    packages=['pybind11'],
     license='BSD',
     headers=[
         'include/pybind11/attr.h',