Massive search-and-replace to eliminate non-unneeded args being passed

Massive search-and-replace to eliminate non-unneeded args being passed
to the read and write inits.
gpx.c had non-mechanical changes for logpoint and urlbase options.

git-svn-id: http://gpsbabel.googlecode.com/svn/trunk@499 f51c46e8-681c-474f-0cfe-069cfd0219fb