Made pages to request a new user account
Made it possible to add a new group
Merge remote branch 'origin/pieterb_vanalles' into niek_vanalles

Conflicts:
	src/beehub_principal.php
	src/beehub_user.php
	src/beehub_users.php
	templates/default.php

Also updated config_example.ini (Pieter forgot to do this)
And removed PROP_NEW_EMAIL, as I don't want to show this internal value to the user
Moved authentication from Apache config (not visible) to PHP
* Authentication is only required/possible of you perform anything but an OPTIONS request over HTTPS (or over HTTP if running in a development environment)
* Authentication is not required if performing a GET, HEAD or POST on the users collection (but it is possible when using HTTPS)
* Authentication is not required if performing a GET or HEAD on the homepage url (but it is possible when using HTTPS)

This makes it possible to integrate SimpleSamlPHP (though this is not yet implemented)

Furthermore I fixed a bug in the beehub_directory view which still pointed to $directory (is now $this)
Homepage and 'sign up' page are now accessible for unauthenticated users
Fixed several bugs with 'virtual' resources which made them need a real file as if they were XFSResources
Fixed some bugs introduced by refactoring the property privilege system
Fixed some bugs with views
Merge branch 'master' of github.com:sara-nl/BeeHub
Werk uit hamburg
Fixed several issues with views and authentication stuff (after first checks on an actual HTTPS system)
nieuwe webdav library versie
nieuwe versie van webdav-php
Merge remote branch 'origin/pieterb_hamburg' into niek_vanalles

Conflicts:
	config_example.ini
	src/beehub.php
	src/beehub_acl_provider.php
	src/beehub_directory.php
	src/beehub_group.php
	src/beehub_principal.php
	src/beehub_principal_collection.php
	src/beehub_registry.php
	src/beehub_resource.php
	src/beehub_run.php
	src/beehub_sponsor.php
	src/beehub_user.php
	src/beehub_users.php
	templates/default.php
	views/header_no_bootstrap.php
	webdav-php

I'm not sure if this was a useful merge