'pex <dir>' doesn't actually work unless an .egg-info is already there
It turns out that pex for some reason generates an .egg-info missing setup.py, which causes 'pex .' to fail in a fresh clone.

``` bash
mba=flask=; ~/clients/pex/dist/pex -v -v -v -v -v .
**** Failed to install Flask-0.11.dev0. stdout:

**** Failed to install Flask-0.11.dev0. stderr:
Traceback (most recent call last):
  File "<stdin>", line 6, in <module>
IOError: [Errno 2] No such file or directory: 'setup.py'
```

diff --git a/pex/installer.py b/pex/installer.py
index 38958a6..17f4970 100644
--- a/pex/installer.py
+++ b/pex/installer.py
@@ -35,6 +35,7 @@ class InstallerBase(object):
   SETUP_BOOTSTRAP_MODULE = "sys.path.insert(0, %(path)r); import %(module)s"
   SETUP_BOOTSTRAP_FOOTER = """
 __file__ = 'setup.py'
+sys.argv[0] = 'setup.py'
 exec(compile(open(__file__).read().replace('\\\\r\\\\n', '\\\\n'), __file__, 'exec'))
 """
 
diff --git a/pex/testing.py b/pex/testing.py
index 7d07310..54c14c0 100644
--- a/pex/testing.py
+++ b/pex/testing.py
@@ -79,9 +79,6 @@ PROJECT_CONTENT = {
           package_data={'my_package': ['package_data/*.dat']},
       )
   '''),
-  'MANIFEST.in': dedent('''
-  include setup.py
-  '''),
   'scripts/hello_world': '#!/usr/bin/env python\\nprint("hello world!")\\n',
   'scripts/shell_script': '#!/usr/bin/env bash\\necho hello world\\n',
   'my_package/__init__.py': 0,
['pex/installer.py', 'pex/testing.py']