December comes around again: homes are filled with good cheer, the collared masses grow eager to spend their hard-earned bonus, and at all hours of the night city streets buzz with merrymaking. Before we know it, the calendar prepares to turn over a new leaf.   For many of us the end comes sooner than we think. Not so for the accountant, who must learn to keep carols alongside vigils. At this time of year, one of the challenges to face is the annualization of employees' compe