Up 'til now ....this means up until this time, (now) examples: Up 'til now, I have had a headache. The pills are finally working and the headache is going away. Up until now I thought you were crazy. Now I KNOW you are...(not just thinking you are, I know you are) (joking).

Up till now, is a little lazy but it is what we would say it sounds more natural but all of the options you have put up are fine. 'Until just now' implies that is it something that has just happened, the others are not such defining statements

The up is repetitive - and often used. It is not needed though. Until now and up till now - do mean what you suggest. Untill now: Throughout the past - but not necessarily including this moment.