kappa: updated configecho documentation and ifd.

The documentation now gives more detail about the new NDF and
APPLICATION parameters.  Also added ppath and vpath values
for these parameters to the kappa.ifd.in file.
kappa: Improved NDF config handling in configecho.

Used ndfBegin and ndfEnd and AST string routines.  Added
more status checking.  Addressed compiler warnings,
improved the error message and updated the DisplayKeyMap
comment.