ISLAM AND LIES?

Someone has asked me whether it is true that lying is permitted in Islam under three conditions:
Lying to non-Muslims when it is in the best interest of Islam.
Lying to Muslims if it will end conflict between them.
Lying to one’s wife to improve the relationship.

Now, I am aware of the various sweeping Islamic injunctions against lying, yet I would need to know if there IS A CASE for lying as above?

Would someone throw light whether this has a religious sanction? Please cite the doctrine, not your opinion, on this