[OE-core] [PATCH 0/1] base/license.bbclass: handle multiple INCOMPATIBLE_LICENSEs

[Andy Ross]

We hit a problem trying to exclude L/GPLv3 recipes where
INCOMPATIBLE_LICENSE could only match exactly one license.  The older
wildcard syntax had been broken by a more recent SPDX change
(specifying a string without a SPDXLICENSEMAP entry could crash), so
"*GPLv3" wouldn't work.

This fixes that, and extends INCOMPATIBLE_LICENSE to handle a
whitespace-separated list of license strings to exclude (e.g "GPLv3
LGPLv3").  This is compatible with existing usage because the LICENSE
parsing is already done on whitespace: a pre-existing
INCOMPATIBLE_LICENSE value with whitespace could not have matched
anything in practice.

All other behavior should be unaffected.  Note specifically that the
LGPLv2_WHITELIST_${license} variables are used as whitelists for all
licenses (i.e. identically to WHITELIST_... and
HOSTTOOLS_WHITELIST_...).  That sounds wrong, but seems to have been
the preexisting behavior.  Ideas?

Andy