Merge pull request #795 from adamjstewart/features/argcomplete

Add argcomplete python package

var/spack/repos/builtin/packages/py-argcomplete/package.py

+from spack import *
+
+class PyArgcomplete(Package):
+    """Bash tab completion for argparse."""
+
+    homepage = "https://pypi.python.org/pypi/argcomplete"
+    url      = "https://pypi.python.org/packages/source/a/argcomplete/argcomplete-1.1.1.tar.gz"
+
+    version('1.1.1', '89a3839096c9f991ad33828e72d21abf')
+
+    extends('python')
+
+    def install(self, spec, prefix):
+        python('setup.py', 'install', '--prefix=%s' % prefix)