Added a main() function to setup.py for more flexibility in organizing its functions.

setup.py

@@ -2,7 +2,7 @@
 # coding: utf-8
 
 """
-This script supports installing and distributing pystache.
+This script supports distributing pystache and testing it from a source distribution.
 
 Below are instructions to pystache maintainers on how to push a new
 version of pystache to PyPI--
@@ -126,7 +126,9 @@ PACKAGES = [
 ]
 
 
-setup(name='pystache',
+def main(sys_argv):
+
+    setup(name='pystache',
           version=VERSION,
           license='MIT',
           description='Mustache for Python',
@@ -168,4 +170,8 @@ setup(name='pystache',
             'Programming Language :: Python :: 3.2',
           ),
           **extra
-)
+    )
+
+
+if __name__=='__main__':
+    main(sys.argv)