Log Message:
Update to 4.8.0.  As a byproduct, update proj-datumgrid to 1.5, which
has an additional grid shift file.  Add a test target; regression
tests now pass at least on NetBSD/i386 5.1_STABLE.

4.8.0 Release Notes
-------------------

 o Added the Natural Earth projection.

 o Added HEALPIX, rHEALPIX and Icosahedral Snyder Equal Area projections.

 o nad2bin now produces "CTable2" format grid shift files by default which
   are platform independent.

 o nad2nad removed, use cs2cs for datum shift operations.

 o projects.h no longer installed as a public include file.  Please try to
   only use proj_api.h.

 o Add pj_get_spheroid_defn() accessor.

 o Added an alternate version of pj_init() that takes a projCtx (execution
   context) structure to address multithreading issues with error management
   and to provide a support for application hookable error reporting and
   logging.

 o Upgrade to EPSG 7.9.  Some changes in ideal datum selection.

 o JNI bindings reworked, org.proj4.Projections deprecated in favor of
   org.proj4.PJ.

 o Added preliminary vertical datum support.

 o Fix various multithreading issues, particular in datum grid handling code.

 o Added support for the +axis= option for alternate axis orientations as
   part of a coordinate system (used for TM South Orientated support).

 o +proj=omerc implementatioin replaced with code from libproj4.  +rot_conv
   flag no longer works, and some coordinate systems (ie. Malaysian) will
   need to use +gamma instead.  "epsg" init file updated accordingly.