Renamed configuration from FileManager's root path to Paths/filemanager_path
Renamed configuration for Navigation app from Navigation/json_file to Paths/navigation_json
Added configurable paths for multi-file and multi-image.
Also fixed bug in js where last_path wasn't being set properly if
the dirname didn't have a trailing '/'.
Created a function to escape strings for RegExp & used it to escape 'filemanager_path' variable.
Removed checking of Paths/filemanager_path and Paths/navigation_json config options within index.php.
Fixed typo in RegExp line of multi-file.js
Made $webroot dynamically updatable by conf('Paths','filemanager_path')
Created default Paths for navigation_json and filemanager_path
Merge branch 'master' of https://github.com/gareththered/elefant