Fix the fetching of demo data

On my system the formatting for time.ctime was different from
what was expected. I changed to using just the time module, which
also simplifies the code.
Started magnification transform
Move magnify example to demo
image magnification example working nicely
Added lines to mag example
magnify works well with forward and reverse mappings
linear mag transform works
better mouse interaction
Fixed python map method
Add fine structure to scatter plot
flakify
Cleanups
Make response to wheel smoother
disable transform for very snall magnification
Docstrings and minor updates
flakify
Move MagnifyTransform
flakify
cleanup
Implement Camera.pre_transform
cleanup