Add remove_jitter and int_exp_norm functions in bq_c
Add tests
Clean up bq_c.expected_squared_mean a little
Keep track of jitters
Add extra jitter to x_c
Plot lines where the x_c are as well
Misc small changes
More misc small changes
Make test_improve_covariance_conditioning more robust
Clean up expected variance derivation a little
Rerun notebooks
Remove xfail decorators
Use 10 instead of 9 samples, and rerun visual-tests notebook