bump version to 0b
forgot to reset cursor on Init()

was not affecting the code as is but it would be a latent bug, or maybe
if one loads two files, the second shorter.
fixed the mouse hit testing at scale != 1.0

finally got the correct transform for the coordinates.
The fact that we don't scale around (0,0) was confusing me badly.

We still have issues hit testing on the last block in view, see 'add EOF
block' commit for more context.