Add main ipython script entry point in same location as before.

IPython/scripts/ipython

@@ -0,0 +1,10 b''
+#!/usr/bin/env python
+"""Terminal-based IPython entry point.
+
+Note: this is identical to IPython/frontend/terminal/scripts/ipython for now.
+Once 0.11 is closer to release, we will likely need to reorganize the script
+entry points."""
+
+from IPython.frontend.terminal.ipapp import launch_new_instance
+
+launch_new_instance()