Also remove all mentions of setupegg.py from the documentation.

[ci skip]

We used to use ``rank`` to mean the number of axes in an array, but no
more.  Change these uses of rank to refer to dimensions.

Closes gh-6839

I've seen at least three occurrences (a couple on stackoverflow, and one
private email) of someone using the argument 'order=15' in a call to the
'set_integrator' method of 'scipy.integrate.ode'.  Presumably this is
because of the suggestion in the "NumPy for Matlab Users" guide to
replace 'ode15s' with 'scipy.integrate.ode(f).set_integrator('vode',
method='bdf', order=15)'.  The stiff solver in 'vode'--presumably the
solver of interest for someone using 'ode15s'--has a maximum order of 5,
and the non-stiff solver has maximum order of 12.  (The maximum order of
'ode15s' is also 5; the '15' in the name refers to the variable order
ranging from 1 to 5.)

Might be useful to someone.

Excised too opinionated parts and replaced most links to specific
software with the topical software page links.