DOC: Add images, refactor.
Remove useless functions, keep some as internal-only.
Use internal fn.
PY3: fix exception style
Cache previous results (speeds up simulations).
Enable caching. Simplify interfaces.
BUGFIX: allow printing of PSS results.
Define the version number in one place only.
MINOR: Change year to 2014.
Bump version to 0.10.
MINOR: Update README.md with v.0.10 info.
MINOR: Update CHANGELOG.md with v.0.10 info.
MINOR: Rename NEWS.md to CHANGELOG.md
Add sim_opts constructor keyword and sim options support.
Delete NEWS.md
Reset sim options before skipping.
Update with master changes.