Remove accidentally committed print() calls
Check for event.inaxes before selecting element

Fixes an exception.
Stop updating views after destroying their panels

Fixes a wx._core.PyDeadObjectError.
Autoscale matplotlib graph after updating curve
Open MAD-X process with STDIN=NULL

This fixes a bug on windows when STDIN is not an inheritable file handle.
Most notably, this occurs when starting as "madgui.exe", i.e. with the
setuptools generated entrypoint.
Merge branch 'various-bugfixes'