test animation capabilities w/ GtkDrawingArea

cairoPoincare.h
* move Point class from testPoincareDisk.cpp
* make drawPoint(), drawLine() and drawUnitCircle() accept cairo_t*

testAnimation.cpp
* animate expanding/contracting {5,1} convex- & {5,2} star-polygons

testPoincareDisk.cpp
* move Point class to cairoPoincare.h