imageio_rawspeed: support single component per pixel sRAWs

Tested with Leica M9 monochrom, and it works, except there are some
color fringing artifacts that need to be further investigated.
adobe_coeff: dummy matrix for leica m9 monochrom
Lens IOP: fix 2 HUGE leaks in `correct` codepath.

Coverity CID 1224432, CID 1224433.
rawspeed: very experimental sony a7s support