Create an IPython siesta analysis tutorial

[zerothi]

• [x] molecule analysis
• [x] non polarised (k)
• [x] polarised (k)
• [ ] non-colinear (k)
• [ ] spin-orbit (k)
• [ ] grid handling
• [ ] wavefunctions
• [ ] integration of stuff

[zerothi]

What would be nice to showcase the analysis off?

[zerothi]

The first two are completed.

[zerothi]

I think the polarized calculation is not needed. The only thing required is to add spin=0|1 here and there...