get_promise
doxygen
Start on promise extraction
Mystère, et boules de vignette
fix dots_environments
arg_env and arg_expr
macros stop using parent.frame
Extracting promises
unpack dots substitutes empty promise for missing arg;

fixes #28 (sort of).
Eliminate many calls to parent.frame()
promise extraction can get ..vars
use allocate_dotslist; delete some junk
Documentation
Remove summarizer and mutator
Remove parent frame from qq
formatting
fun documentatation
CRAN prompted fixes, use rm(list=<...>, envir=x)
qqply no longer uses .Internal(mapply), per CRAN

involved mostly reimplementing mply, should refactor that.
also: fixed dots_*() when called with no args.
(should just delete these as `dots_expressions(...)` is no more
efficient than `expressions(dots(...)))`
vignettes not ready for prime time