Use find_packages + manifest update

Author: einarf

MANIFEST.in

@@ -1,3 +1,4 @@
-recursive-include demosys *.py *.glsl *.png
+recursive-include demosys *.glsl *.png *.jpg *.json
 
 include README.md
+include LICENSE.txt

setup.py

@@ -1,4 +1,4 @@
-from setuptools import setup
+from setuptools import setup, find_packages
 
 setup(
     name="demosys-py",
@@ -11,7 +11,7 @@
     author_email="eforselv@gmail.com",
     maintainer="Einar Forselv",
     maintainer_email="eforselv@gmail.com",
-    packages=['demosys'],
+    packages=find_packages(),
     include_package_data=True,
     keywords = ['opengl', 'framework', 'demoscene'],
     classifiers=[