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

New wildcard support. Lightly tested, so proceed with caution. We need to sync this on the nbshell/chainsaw branches.

Doc updates about demos...