Make the default name of undefined axes axis%i
Add gui.axes.navigation_sliders
Enable slider when navigation_dimension > 2
Revert "Remove EELSCLEdge.energy_shift parameter"

This reverts commit 4e2404b6071b58d596a5c9e286f094c78a68bcdf.
BugFix: added conservation of instance type to split_in
Improved solution following Francisco's suggestion in github
Revert "Revert "Remove EELSCLEdge.energy_shift parameter""

This reverts commit dd4b9304896723b4c929b685c695fd394c12dac0.
Merge branch 'fix_split_in' of github.com:hyperspy/hyperspy into fix_split_in