Namespace fixes for embedded instances, as well as tab-complete enhancements in that context. Full details in changelog

- Fairly significant changes to include Vivian's patches for improved pdb support. Her original idea was kept in full, code reworked for compactness and better integration with the rest of ipython. - Added download_url arg to setup.py to support setuptools.

Fix mainloop() call form which was inconsistent across shell classes

Updated manpage and docs to clarify negated options usage. Thanks to Stefan van der Walt for the heads-up.

Put .rc attribute in instance earlier, too many methods expect this to be there and it could lead to weird runtime bugs (like the one fixed by the previous commit).

Fix crash with a naked 'alias' call in ipythonrc file.

Wildcard system cleanup, ipmaker speedups, bugfix in globals handling (previous fix had introduced a problem). Changelog has more details.

wildcard fixes for subclasses

Fixes for handling of global variables in embedded ipython instances (I ran into the bug while trying to fix a bug in scipy's polynomials module).

Update about DarwinPorts install