use the Apache `SCRIPT_URL` var to reconstruct a logial `SCRIPT_NAME` when mod_rewrite is in use (fixes #2299)
use the Apache `SCRIPT_URL` var to reconstruct a logial `SCRIPT_NAME` when mod_rewrite is in use (fixes #2299)

git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@4718 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac