Don't assume folder name is always 'newscoop/'

The Newscoop root folder can have different names on the users' systems, such as a username, domain name or 'public_html'. In these four files, the path is set to a folder named 'newscoop', which can result in errors. 
The fifth file that had this error, library/Newscoop/Gimme/PropertyMatcher.php, seems to have been fixed already on the master.