maketx speedups: avoid initial resize when the input image is already pow2, and for mipmap level downsampling to simply average groups of 4 pixels instead of the equivalent (but more expensive) linear interpolation.  Add timers so that "maketx -v" will report how much time is spent on various major tasks.  And finally, some minor changes to the status message and formatting.
maketx speedups: avoid initial resize when the input image is already
pow2, and for mipmap level downsampling to simply average groups of 4
pixels instead of the equivalent (but more expensive) linear
interpolation.  Add timers so that "maketx -v" will report how much time
is spent on various major tasks.  And finally, some minor changes to the
status message and formatting.


git-svn-id: c3edda122e248ef33995da003806c930f62b9468@699 31904243-a364-42ac-a3db-9305396518ba

mcanthony/oiio,micler/oiio,jeremyselan/oiio,cwilling/oiio,bdeluca/oiio,lgritz/oiio,mcanthony/oiio,bdeluca/oiio,bdeluca/oiio,OpenImageIO/oiio,lgritz/oiio,OpenImageIO/oiio,cwilling/oiio,micler/oiio,scott-wilson/oiio,OpenImageIO/oiio,micler/oiio,sambler/oiio,YangYangTL/oiio,scott-wilson/oiio,lgritz/oiio,sambler/oiio,bdeluca/oiio,jeremyselan/oiio,mcanthony/oiio,sambler/oiio,YangYangTL/oiio,sambler/oiio,OpenImageIO/oiio,scott-wilson/oiio,scott-wilson/oiio,micler/oiio,jeremyselan/oiio,YangYangTL/oiio,YangYangTL/oiio,lgritz/oiio,cwilling/oiio,cwilling/oiio,mcanthony/oiio