Load of nupoint from Narwhal to github(erex)

Code has been de-MVBed and has had comments placed into roxygen2 mode.
There are several place-holder functions that perform no analysis, and
the package also lacks the two datasets (krill and sightings).  Without
those objects, the .Rd files (originally sent by Martin) are not
currently present
Revert "Load of nupoint from Narwhal to github(erex)"

This reverts commit 463858a824000a11f4b5d6eb84773be3aaed0c58.
from Narwhal to github
From Narwhal to Github
Update readme
strong and manuscript added
removed 'built' and 'collated' from Description

also increased version number to 1.0.50
Update README with full citation for MEE paper
Update README
more functions made part of package from workspac

several functions formerly resided in the .RData workspace and not
explicitly as functions in the package these included
pi.z.f, par.unpack, bound.chk
remaining function moved from workspace

last of the functions made stand-alone files with Roxygenised
documentation
Documentation for package and for sightings

Continued tidying of documentation
Large changes to simulator and estimator shore

DLB revised both numerator and denominator of likelihood for vantage
points.  ER made changes to env.simulator so that subscript bounds were
not exceeded when assigning simulated cues to grid locations
abundance estimation initial steps

abs(dzdy) in mles as well as beginnings of abundance estimation routine
first requiring truncation (done by truncate.r) and testdavid.r contains
abundance estimation (to be cleaned)
abundance estimation from simulated (few models)

Abandoned hope of unifying abundance estimation for both simulated and
actual data.  Data structures for real and simulated data are
sufficiently different that I could not made two data types congruent to
live within functions.

I have also abandoned ability to produce bootstrap estimates of
precision in abundance estimates.

This commit contains functions that can produce point estimates of
abundance for simulated data under half-normal detection and normal
gradient models only.
est.abund mods to estimate under true/false model

est.abundance.from.sim altered so arguments can specify models under
which to estimate abundance.  If NULL then estimation is under true
models.

Example extended to show use.  Example is convenient because of the 4
models fitted, AIC is smallest for true model.
Extended est.abundance.from.sim example

Comment suggesting user look at AIC scores
sort out NAMESPACE

added @export to roxygen comments of several functions.  This properly
created the NAMESPACE and DESCRIPTION files.  Now only select functions
are exposed (e.g. detectF) while other functions (e.g. pi.z.f) are only
visible if explicitly using namespace (nupoint:::pi.z.f).

Bumped package number to 1.0.52