Worthwhile comments thanks to Øyvind Kolås, 2008-10-19 14:52:20

Comments for _bezctx structure duplicated from gegl commit on 2008-10-19.
Enable VERBOSE flag in library using ./configure

Made it so that several printf() statements inside #ifdef VERBOSE wrappers
can be enabled during ./configure. This is only a debugging option since
most users won't want to see or be printing values to the command line.
Quiet some compiler warnings (...warning: no previous prototype for...)
Enable CHECK_INPUT_FINITENESS flag in library using ./configure

Seeing additional checks for finiteness added earlier, investigated into
doing checks early, and exiting early if problem encountered. Looking at
FontForge, GEGL and Inkscape, they already take care of their own inputs
so this "check" seems unnecessary and therefore added as an option. Kept
this so that it somewhat helps "document" inputs via printf() statements
Pass nmat variable to reduce repeatedly recomputing with count_vec()