[horde] More errors with PHP 7

[Twilek]

I am seeing even more errors with PHP 7. When opening the horde  
configuration page (config.php?app=horde) this shows up:

  UNCAUGHT TYPEERROR: ARGUMENT 1 PASSED TO  
IMP_APPLICATION::EXCEPTIONHANDLER() MUST BE AN INSTANCE OF EXCEPTION,  
INSTANCE OF PARSEERROR GIVEN IN  
/VAR/WWW/WEBMAIL/IMP/LIB/APPLICATION.PHP:610 STACK TRACE: #0 [INTERNAL  
FUNCTION]: IMP_APPLICATION->EXCEPTIONHANDLER(OBJECT(PARSEERROR)) #1  
{MAIN} THROWN

  1. Horde_ErrorHandler::catchFatalError()

  DETAILS

  Die Vollständige Fehlermeldung Wurde In Hordes Logdatei Geschrieben  
Und Für Administratoren Weiter Unten Ausgegeben. Benutzer, Die Keine  
Administratoren Sind, Bekommen Diese Details Nicht Zu Sehen.

  ErrorException Object (     [message:protected] => Uncaught  
TypeError: Argument 1 passed to IMP_Application::exceptionHandler()  
must be an instance of Exception, instance of ParseError given in  
/var/www/webmail/imp/lib/Application.php:610 Stack trace: #0 [internal  
function]: IMP_Application->exceptionHandler(Object(ParseError)) #1  
{main}   thrown     [string:Exception:private] =>       
[code:protected] => 0     [file:protected] =>  
/var/www/webmail/imp/lib/Application.php     [line:protected] => 610    
   [trace:Exception:private] => Array         (             [0] =>  
Array                 (                     [function] =>  
catchFatalError                     [class] => Horde_ErrorHandler       
                [type] => ::                     [args] => Array        
                   (                         )                  )       
     )      [previous:Exception:private] =>      [severity:protected]  
=> 1     [logged] => 1 )
This is far beyond my programming abilities (which are not that great  
actually). Maybe someone can use this to make horde more PHP 7  
compatible....