added progress callback activation to buildCb
minor text wrap around
added cylinder to Csg
bugfix: if there are no front/back polygons, we shouldn't
create a front/back bsp node.
The result of doing some profiling on the dot product

Apparently, returning the value from the other vector
results in the semaphore being activated in the V8 engine
changed bsp_test's sphere exercise into a benchmark
some test cases for trying out go.
added flip to polygons
added timed CSG difference