New formulas: goocanvas and gpredict

Gpredict depends upon goocanvas so this is a request for adding both formulas.

goocanvas - GooCanvas is a canvas widget for GTK+ that uses the cairo 2D library for drawing.

gpredict - Gpredict is a real-time satellite tracking and orbit prediction application. It can track an unlimited number of satellites and display their position and other data in lists, tables, maps, and polar plots (radar view). Gpredict can also predict the time of future passes for a satellite, and provide you with detailed information about each pass.