- methods formerly taking a const reference to Problem as input now take
    a shared pointer to const Problem.

  - add assert to check that tests are always false.

Fix C++98 compatibility.

Update to modifications in hpp-constraints

  - Specify comparison types in implicit constraint constructors.

  constraints::implicit::RelativePose has been removed.

  - replace call to deprecated method,
  - include amsmath package to generate documentation,
  - fix unit test.

  - Refactoring of ConvexShapeContact.

[ROS] Add package.xml

  Set error threshold for each internal edge to the value of the edge divided
  by the number of internal edges.

  in throwIfNotInitialized.
  This modification allows users to access constraints of some edges during
  graph initialization, as soon as those edges are initialized.

Refactor Edge class and derived classes

  -> generateTargetConfigOnLeaf.

  - reference ICRA 2017 paper.

  Make previous methods deprecated
  Rename Graph::configConstraint(EdgePtr_t) into targetConstraint.

  remove unexisting input.