Fix password authentication for links and fix template problems for links by creating a new base layout

LDAP: check for existing username from other backends when creating one for an LDAP user or group. Led also to some code cleanup. Fixes oc-1551 in master.

LDAP: implement getHome() function, use either username (default) or specify an LDAP attribute value to use

LDAP: transliterate other latin characters to ASCII when creating owncloud names. Already created usernames are not being affected.

https://github.com/owncloud/core/commit/2028c8116122f56d8087716e42162fdc
651819d3#commitcomment-1766755

OC_Util is better thank OCP\JSON because it'll redirect the user to the index.php instead of displaying an error

OC_Share no longer exists. remove hooks that would trigger require_once / autoloading failures, so i can at least upload files