Add measures on the Circle

[sethaxen]

Add the following measures from Mardia & Jupp. Directional Statistics. 2000:

• [ ] Hausdorff/Haar
• [ ] von Mises
• wrapped:
  • [ ] Gaussian/Brownian motion
  • [ ] Cauchy
• [ ] Projected normal

Also the following from Pennec. Intrinsic Statistics on Riemannian manifolds:

• [ ] Riemannian normal/Normal law