The fix in #22 solved the problem at hand and doing what was expected
from the specified parameters. Unfortunately it also removed the slightly
hacky "feature" that makes the web mercator work in pj_transform. The
web mercator is special since the latitude is computed on the ellipsoid,
but behaves as if if was defined on a sphere. Hence it is problematic to
change the ellipsoid parameters when using the web mercator, even though
that is the geodetically correct thing to do. The web mercator is used in
more or less any web mapping application and is thus one of the most
frequently used transformations in PROJ. This justifies re-introducing
the minor bug reported in #22.

The problem will have to be taken care of properly when pj_transform
is removed from the library in favour of the transformation pipelines
based API.

Make sure to not change ellipsoid parameters to WGS84 when applying the
null grid. Coordinates will still refer to the input ellipsoid so we
keep the original parameters which in turn will be used when the
coordinates are transformated to/from cartesian/geocentric space.

Adjusted regression test material in nad/proj_outIGNF.dist slightly to
accomodate numerical differences at the mm level. The transformations
in question are at best accurate to about 1m so this shouldn't change
real world usage of these transformations.

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@2188 4e78687f-474d-0410-85f9-8d5e500ac6b2

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@1672 4e78687f-474d-0410-85f9-8d5e500ac6b2

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@1433 4e78687f-474d-0410-85f9-8d5e500ac6b2

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@1430 4e78687f-474d-0410-85f9-8d5e500ac6b2