* Avoid using angle brackets for PROJ headers.

Switching from #include <proj.h> to #include "proj.h",
and correspondingly for projects.h and proj_api.h,
reduces the risk of accidentally picking up a system
installed older version of the header while building
a new version of PROJ.

* Also handle geodesic.h

Decisions regarding the size of certain types are always made at
compile time, hence this is where the assertion should take place.

If the assertions fail, there is now a compiler error.

* Handle allocation failure when loading grid files

Continuing #606, we tackle the same issues in the loading and processing
of grid files. This should fix potential crashes and memory leaks, and
makes sure the global lock is always released.

* Use pj_calloc when zero-initialized memory is wanted

In most cases memory deallocation is completely removed from the
code since it can be handled by the default destructor. In a few
special cases a local destructor overrides the default destructor
and makes sure that locally allocated memored is cleaned up correctly.

Move all deallocation from pj_free to pj_default_destructor
Rename pj_latlong.c to fit with the conventional format PJ_latlong.c - freeup was missed here due to wrong naming
Clean up pj_init to avoid double deallocation; Also resolve #576 by adding z_0 and t_0 options in pj_init, while cleaning

Add a prototype for dealloc_params
Added missing errno.h include in pj_ctx.c
Temporarily removing ob_tran from testvarious, to be sure that is where the trouble is
Make PJ_ob_tran.c use proper initialization for the chained projection
proj=ob_tran: make it clear, that we disallow ellipsoidal projections, and, for improved backwards compatibility, turns off default settings, which could inject unwanted ellipsoid definitions
... then also remove the ellipsoid definition from the testvarious test case - which is probably buggy anyway
Work around cs2cs spherical init bug in testvarious; Forbid defs for ob_tran in pj_init

When gridloading fail for one grid, but return a gridlist, we leak the grid list array.
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2230. Credit to OSS Fuzz