Rename hpp-fcl repository fcl -> hpp-fcl.
Reoganize dependencies

  - hpp-constraints now depends on hpp-model,
  - hpp-core now depends on hpp-constraints,
  - dependency to roboptim has been removed.
Reverse order of packages hpp-core and hpp-constraints.
Add link to hpp-manipulation-urdf
Add link to hpp-util
target status in Makefile check its own status
Add link to hpp-statistics
Use billx09 repo instead of hpp repo