merge 1.8.1 to head
use {$contextURL} and {$cgi-prefix} param for absolute paths (instead of relative paths)
add default value to 'cgi-url' param.
Turnkey installer modifications: add 'cgi-url' param via skin configs.
Turnkey Installer modification: remove locale specific ant tokens with relative paths.
Changes in login processing to match new register-dataset.cgi workflow: user must login before seeing the form, to prevent data loss. New template login.xsl provides simple redirection back to register-dataset.cgi.