Be reproducible, and don't fail on examples exceptions

Be reproducible, and don't fail on examples exceptions

Don't execute example notebooks because some of them
have unreproducible output, either numerical differences (small
enough that I guess them to be machine-dependent rounding error
not deliberate randomness) or extra cells (a single newline
being split into its own cell vs part of the previous one).
Copy them instead.

At one point these 10 were affected, but skipping just them doesn't
work because it seems 'random' which ones have the extra cells.
count_hurdle
discrete_choice_example
discrete_choice_overview
exponential_smoothing (and its images 14_0 and 16_0)
generic_mle
glm_formula
glm_weights
postestimation_poisson
stats_poisson
treatment_effect

Also remove timestamps, ipykernel IDs, etc from examples output
for reproducibility.  (This is here not in debian/rules to do it
before building the search index.)

Skip some vector_ar cells that would print <type at address>
output (that would end up in the search index, so
stripping it afterwards isn't enough).

Author: Rebecca N. Palmer <rebecca_palmer@zoho.com>
Forwarded: not-needed

Gbp-Pq: Name sphinx_reproducibility_and_ignore_errors.patch