Vol Cube reshape speed up

[tleitch]

Used assignInNamespace and reshape2 functions instead of for loops. No changes to library functions.

[eddelbuettel]

That looks fine but I don't quite understand why it is seven commits.

[eddelbuettel]

Conceptually speaking, and I do this all the time, we can do:

• start from the master of this repo, head commit 2990cac72a25056a0b43a505f3348d34a0276ea4 from two days ago
• create a branch
• modify the two files affected here: server.R and volDF2CubeK.R (which could be in server.R too)
• commit (one commit)
• create PR

Cleaner?

[eddelbuettel]

I cherry-pick'ed the one commit that mattered from https://github.com/eddelbuettel/rquantlib/pull/69/commits/428b7ca67e4708035b8fab191eba8b875d70d1bd.