Log Message:
Update to 7.0.4

Changelog:
Version 7.0.4 Dec 9th 2014
Added XMLWriter check
Better deleted outdated previews
Store storage credential in session only if needed
Don't disclose relative directory path for single shared files of user
Password reset fixes
Fix enable app only for a specific group
fixing port configuration in trusted domains
LDAP fixes
Make group search case sensitive
Allow admin to change users display name
ldap performance improvements
config.php can now be read only
Several smaller fixes