Changed way to get error group code from $code parameter.

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Changed error handling on ajax requests.

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Removed not needed Lib parent

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Changed all public methods to be final to prevent overriding.

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>
Changed class to be final. 
Removed not needed static property $instance.
Change error() method to use html() with paramters.

Signed-off-by: Michael 'Tekkla' Zorn <tekkla@tekkla.de>