License Change checking:
Added a new variable in recipe : LIC_FILES_CHKSUM
It is a required field for every recipe.
It describes license text location in the source files. And also stores
md5sum of that license text. Any change in this license text triggers build
error. Which enables developer to review any changes in the license and
update the license fields in the recipe accordingly.
For Example: contents of zlib_1.2.3.bb
LICENSE = "zlib"
LIC_FILES_CHKSUM = "file://README;md5=
ae764cfda68da96df20af9fbf9fe49bd \
file://zlib.h;beginline=1;endline=30;md5=
6ab03f03a5ee92d06b809797d4d5586d "
Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
