2.0.0 Beta 1

• Process::__construct() is now private in favor of Process::start()
• Process::start() is now static instead of an instance method
• Process::start() does no longer return the PID, use Process::getPid()
• Process::kill() does no longer result in an exception of Process::join()
• Process::getEnv() has been renamed to Process::getEnvironment()
• Improved handling if process is destructed, but streams are still used
• Renamed escapeArguments to escapeArgument
• Removed custom stream implementations
• Removed StatusError