CRM_Core_PseudoConstant::greeting() cache bug

CRM_Core_PseudoConstant::greeting() will cache in CRM_Core_PseudoConstant::$greeting. The cache is populated only once but the cache is incomplete - it is dependent on the value of $filter. If CRM_Core_PseudoConstant::greeting() is called again with a different value for $filter, the cache (populated using the original value of $filter) is consulted. The function then returns this cached value which is incorrect for other values of $filter.