CI_URI changes related to the 'permitted_uri_chars' setting

 - Initialize and cache the value in the class constructor instead of searching for it every time
 - Removed the preg_quote() call from _filter_uri() to allow more fine-tuning from configuration
 - Renamed _filter_uri() to filter_uri() - it was public anyway and using it cannot break anything

Related: issue #2799
6 files changed