Changes from 1.4:

limn.h:
- API CHANGE: limn is stupider about lights- there is no more
notion of have a collection of "set" lights, and no more
ability to turn on lights without knowing the index of the
light.  So now limnLightSet() requires an index "which".
Also, in the limnLight struct, it is the _dir vector which
is set by the user (via limnLightSet()), and then the
dir vector is either copied from _dir (world space lights)
or transformed through V2W (view space lights).
- API CHANGE: limnLightToggle() renamed limnLightSwitch()
- #DEFINE RENAME: LIMN_MAXLIT --> LIMN_LITE_NUM
- API NEW: limnLightReset() initializes lights

light.c:
- all changes associated with simplifying the limnLight
struct, and swapping roles of _dir and dir; see limn.h
changelog

Makefile:
- added test/tcam.c, a little program for demonstrating
calculation of world-to-view and view-to-world transforms
given from,at,up locations

hest.c:
- clarified command-line flags for limn cam parameters

test/light.c
- fixed to comply with Teem-1.4 limnCam, and with post-1.4
changes described elsewhere
