Xtrack version 0.95.0

Changes:

• Fixes in native MAD-X loader: thin solenoid, k2 in bends, k0 differing from h. Extend knl/ksl when needed.
• Improved atomic_add C function
• Store angles instead of sin/cos in misalignments
• Add k2 attribute to Bend and RBend
• Support thick slicing of misaligned elements
• Support spin tracking for misaligned elements
• Support and set the nocharge option in the MAD-NG interface

Full Changelog: v0.94.2...v0.95.0