New apitools version from internal.

* Fixed an install snafu with `ez_setup`.
* Added a `MANIFEST.in`.
* Working on better `Download` support.
* Better errors for download failures.
* Add a script at install.
diff --git a/MANIFEST.in b/MANIFEST.in
new file mode 100644
index 0000000..fc80ed3
--- /dev/null
+++ b/MANIFEST.in
@@ -0,0 +1,4 @@
+include *.py
+include *.txt
+include *.md
+recursive-include apitools *.py