Remove readIfExists

See http://nodejs.org/api/fs.html#fs_fs_exists_path_callback

In particular, checking if a file exists before opening it is an anti-pattern that leaves you vulnerable to race conditions: another process may remove the file between the calls to fs.exists() and fs.open(). Just open the file and handle the error when it's not there.
Fix settingsLoader

Merge local and global settings object instead of just taking care of contentExtension.
add 	isDescendantOfActive