Squashed commits:
[ac5bb36] Bump version: 0.1.8 → 0.1.9
[8acd6b2] ImportException --> ImportError
[ac410a8] matplotlib.pyplot has errors on import, put these in the functions
that rely on them directly.
[f128a20] Bump version: 0.1.6 → 0.1.7
[5866bea] Remove IPython utils.
These are out of date, and have problems on Linux (without a proper
visual backend).
[a519e56] Bump version: 0.1.5 → 0.1.6
[f45aa83] Bump version: 0.1.4 → 0.1.5