IdP: multiple group rules for ${u} and ${g}

until now, ${u} would match all users,
${u%-foo} would exclude users in group foo,
${u%+foo} would only include users in group foo

now, the following is also possible:
${u%-foo,%-bar} excludes users in group foo and/or group bar,
${u%+foo,%+bar} only includes users which are in groups foo AND bar,
${g%-foo} skips group foo (includes all others),
${g%-foo,%-bar} skips group foo and/or bar (includes all others)

see ./docs/examples/docker/idp/copyparty.conf ;
https://github.com/9001/copyparty/blob/hovudstraum/docs/examples/docker/idp/copyparty.conf

docs/examples/docker/idp/copyparty.conf

@@ -106,3 +106,10 @@
   /w/tank1
 [/m8s]
   /w/tank2
+
+
+# some other things you can do:
+#  [/demo/${u%-su,%-fds}]   # users which are NOT members of "su" or "fds"
+#  [/demo/${u%+su,%+fds}]   # users which ARE members of BOTH "su" and "fds"
+#  [/demo/${g%-su}]         # all groups except su
+#  [/demo/${g%-su,%-fds}]   # all groups except su and fds