Changes

Making CLUBB's splatting scheme implicit and smoother (#1075)

* Introducing rough implicit splatting scheme into CLUBB.  Not yet implicit for wp3.

* Implementing implicit splatting for wp3.

* Further improvements to implicit splatting code, including

- smoothing of the BV freq used for splatting
- adding a new variable 'bv_freq_sqd_splat' to stats
- add the new variable to pyplotgen standard output

See PR #1075 and issue #994.

* Some cleanup.

* More cleanup, and adding comments.

* More comments.

* Updating implicit splatting scheme.

* Updates to resolve PR requests.

Updates associated with implicit splatting will be BIT_CHANGING.