added $webappJsPattern to header.php; WEB_APP_PATH is now defined in bootstrap.php; changed WEBAPP_JS to WEBAPP_JS_URL and also moved it into bootstrap.php; bits\Strings.php::exportStr and ::debugStr will not perform any replacement on "\n" if null is passed into 2nd parameter.

Signed-off-by: baracudda <ryan.fischbach@istresearch.com>