Fixed MANIFEST.in; setup.py now provides an error message about pandoc.

MANIFEST.in

 include README.md
 include HISTORY.md
 include LICENSE
-include DESCRIPTION.rst
+include setup_description.rst
 include tox.ini
 include test_pystache.py
 # You cannot use package_data, for example, to include data files in a

setup.py

@@ -164,8 +164,8 @@ def make_description_file(target_path):
     """
     # Comments in reST begin with two dots.
     intro = """\
-.. This file is auto-generated by setup.py using pandoc, so any edits
-.. should go in the source markdown files.
+.. This file is auto-generated by setup.py for PyPI using pandoc, so this
+.. file should not be edited.  Edits should go in the source files.
 """
 
     readme_path = convert_md_to_rst(README_PATH)
@@ -224,10 +224,18 @@ def convert_md_to_rst(path):
     temp_path = make_temp_path(path)
     print("Converting: %s to %s" % (path, temp_path))
 
+    if os.path.exists(temp_path):
+        os.remove(temp_path)
+
     # Pandoc uses the UTF-8 character encoding for both input and output.
     command = "pandoc --write=rst --output=%s %s" % (temp_path, path)
     os.system(command)
 
+    if not os.path.exists(temp_path):
+        s = ("Error running: %s\n"
+             "  Did you install pandoc per the %s docstring?" % (command, __file__))
+        sys.exit(s)
+
     return temp_path
 
 

setup_description.rst

-.. This file is auto-generated by setup.py, so it should not be edited.
+.. This file is auto-generated by setup.py for PyPI using pandoc, so this
+.. file should not be edited.  Edits should go in the source files.
 
 Pystache
 ========