bootstrap: consistently use correct copyright year Suggested by Peter Johansson in the discussion about automake bug#11356: <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=11356#41> * boostrap.sh (dosubst): Don't initialize the substituted value for the release year from the current year (using `date +%Y`); instead, do it through ... ($RELEASE_YEAR): ... this new statically-defined variable. To ensure it won't get out-of-sync, it will be automatically updated ... * Makefile.am (update-copyright): ... by this target's recipe. Since are at it, fix a botched output redirection for an error message, i.e., use ">&2" instead of ">&1". Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>