wrapping up some blur work prior to pull
Merge branch 'integration' of https://github.com/tipam/pi3d into integration
blur demo and shaders. THIS ONLY HALF WORKS. But I cant figure out how to fix it!
defocussing with distance now works. Thanks PeterO
adding docstrings and tidying
Camera.translate now called position
just checking if we can have a different readme in integration branch
demo running instructions added
demo running instructions added
demo running instructions added
minor tidies
docstrings
adding docstrings
adding docstrings
adding docstrings
adding docstrings
adding docstrings
Ooops - move pi3d.util.Log to echomesh.util.Log
shadows on bumps fit in with light direction
Implement InputEvents subsystem and update Silo.py to use it.

Also minor changes to Silo.py for rotate direction, uncomment mouse button
movement (and correct it). Toggle commenting on record vs. screenshot
since record tries to write to a specific mounted device.