Initial versions of kc2iasi.m and iasi_decon.m.  iasi_test1.m
calculates IASI and AIRS reference truth, and decon_test.m is
just a simple demo.
snapshot with results as reported in the 22 July 2014 blog post
"first look at an IASI to AIRS translation", including an early
version of the iasi2airs.m user interface.
Merge branch 'master' of github.com:strow/iasi_decon
added user demo demo1.m for iasi2airs.m.  This works OK but
iasi2airs uses uses mksconv2, which sorts the AIRS channel set.
That was needed for the AIRS deconvolution, where we also had
to add a minimun channel spaceing, but is not needed here.