Vidhu refers to Sri Krsna. Vidhu, Krsna excels in all excellent qualities (Vidhu Jayati). he who is marked with Srivatsa symbol." indicates a general form of the lord who makes succesive apperances in the world. It also specifically indicates Krsna. The reason is this: Vidhu stands for vidhunoti, which means "he defeats." it indicates the person who transcends all suffering or the person who surpasses all other things. Vidhu can also stand for Vidhati, which means "he produces." the person who produces all happiness, or the person who cause everything in this way. the meaning of vidhu can be derived. COnsidering this factor s one can come to the conclusion about the meaning of Vidhu.
One must conclude that Vidhu means Krsna! He alone is famous for his ability to liberate even demons.( and thus destroys even their suffering) He alone is famous for his ability to surpass all others by his powers. He alone is famous for bestowing happiness- up the greatest happiness found in his most astounding prema. He alone is famous as Svayam bhagavan, the original cause of everything.