ChangeLog:
* configure: Rebuilt.
config/ChangeLog:
* acx.m4 (NCN_STRICT_CHECK_TOOLS): Mark environment variable as
precious.  Prefer it over a cached value.  Use cached value
verbosely.
(NCN_STRICT_CHECK_TARGET_TOOLS): Likewise.  Don't override
environment variable with build-time tools.

From-SVN: r122108