firefox-7 and environment, startup script

[Wolfgang Jenkner]

> +-          "/usr/lib/mozilla/plugins";
> ++          "%%LOCALBASE%%/lib/npapi/symlinks/firefox";

This doesn't work for graphics/gnash (and perhaps other plugins):

$ (cd /usr/ports/graphics/gnash; make -VWEBPLUGINS_DIR)
/usr/local/lib/browser_plugins/gnash
$

The value comes from www/firefox/Makefile.webplugins, I think, and
actually corresponds to the first component in MOZ_PLUGIN_PATH (see
www/firefox/files/patch-build_unix_run-mozilla.sh).

Wolfgang