[Proj] preferred documentation

[Greg Troxel]

I'm the maintainer of the pkgsrc entries for proj and associated
documentation.

Currently, misc/proj-docs packages the contents of
ftp://ftp.remotesensing.org/proj/proj-pdf-docs.tar.gz

The new documentation renders better, and is said to have the same
content.

So, I wonder if the 4 old files should be moved to old_docs, the new
ones promoted, and proj-pdf-docs-1.1.tar.gz created with the 4 new
files.  (I say 1.1 because pkgsrc has called the old file 1.0 for want
of a version number.)