Log4ALA 2.3.4

Optimize json detection (now the detection will only be done if the log message really contains a json string to increase the performance by avoiding unnecessary exception flooding during the json check) and add new properties keyValueSeparator and keyValuePairSeparator to configure any other single char or multiple chars as separator for the keyValue detection in the log message (https://github.com/ptv-logistics/Log4ALA#features under bullet point 9)