Fix issues when APP_LOG is empty, unwritable , or pointed at a directory.
APP_LOG takes precedence over $config['log_file'] now.
DO NOT DELETE THIS TEXT
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* Don't check file permissions on every request, handle failures
Improve error page visually
* only print minimal mkdir
* invert file_exists check, whoops
* docblock
* revert accidental changes
* rename variable
* Change database errors to use the new layout
* Add support url to the default layout
* Replaced \n for && in fix for user perms
* fix web output
