QIX autogeneration and issue notification

[pramsey]

For new users, add the ability for mapserver to autocreate qix files when missing and autoupdate them when they are out-of-date. This ability should be quite optional in that

• it should only exist when mapserver is compiled --with-auto-qix
• it should be optionally suppressed with a map file directive

Also add the general feature that puts messages into msDebug

• when qix files are missing
• when qix files are out of date

this functionality will be part of the standard build.