Add Roxygen docs to equal.lengths()

Roxygen also overwrote the DESCRIPTION and NAMESPACE files.
Add roxygenize() to the test file.
Move helper functions into their own files.

I'm getting some weird errors about how is.wholenumber can't be found.  Plus,
I'm not entirely sure how Roxygen will handle having multiple functions per
file... we'll see how this goes.
Convert qft.interp() to Roxygen2
Convert tspot.interp() to Roxygen2
Add the trim.output dependency to the interp functions.
Some updates by roxygen
Use roxygenise() instead of document().

One is for roxygen, one is for roxygen2... Still doesn't fix my collate problem.
Also standardized to lowercase .r
file extensions.
All lowercase function extensions, plz
Fix \dontrun tags on equal.lengths examples.
Skip the collate roclet for now.

Since the Collate entry in DESCRIPTION is screwing up my tests - skip it.
Don't seem to need it, anyway.
Make Roxygen2 doc blocks continuous.

Seems like they have to be continuous blocks of #' marked code in order to
work - no problem.
Single author entry, proper email tag.
Fix equal.lengths argument documentation.

vec.list is internal to the function, not the argument name - and, because
of the way the function works, it can't really have a single argument name.
So it's just ... - and I'll document that.
Convert the package-help to Roxygen, too, why not
Updated TODO
Remove empty Depends: in DESCRIPTION - now collate works!

This empty Depends: statement was screwing up read.dcf()'s reading of the file.
Now that it's gone, the Collate: section reads in just fine.  No more need to
skip the collate_roclet.
Remove empty Depends: in DESCRIPTION - now collate works!

This empty Depends: statement was screwing up read.dcf()'s reading of the file.
Now that it's gone, the Collate: section reads in just fine.  No more need to
skip the collate_roclet.

Hats off to Hadley Wickham for identifying the problem!
Merge branch 'roxdocs' of github.com:mmparker/tbdiag into roxdocs
Beat this thing into shape for reinstallation.