GRAILS-10753 Console Colors in Windows - optional fix

Outputs the ANSI reset sequence and flushes the stream before the System.exit() invocations to make sure that the console has been reset to its default state. 
The potential problem could occur when the out stream has not been fully flushed and the System.exit() invocation finished. 
Last characters of the out stream contain the ANSI reset sequence - if they are not flushed the console keeps the formatting of the previous message.