check if file exists before loading project
add ability to change log level
add support for changing verbosity in CLI
add support for loading script file

- rename executeScript to executreScriptCommand
- add exeectureScriptFile
improve CLI script execution

- introduce ScriptEngineRuntime (equivalent of WebEngineRuntime for Nashorn)
- improved boot.js to support SetTimeout, SetInterval etc.
- update CLI to use ScriptEngineRuntime
fix bug in loading function: wrong if condition
fix template bug in error reporting
improve logback template

- remove logback configuration debug log
- add log to file configuration
- simplify log output
- set verbosity to ERROR by default
fix for consistent error logging.