if starting configuration slightly violates the constraint.
  Return false instead.

This reverts commit 0d81bac3.

  - only before initialization.

  - remove duplicate loop.

  - GraphComponent::numericalConstraints is virtual,
  - reimplemented in Edge a follows:
    - if edge is not initialized, call parent implementation,
    - otherwise return constraints that are in the solver.
  - The differences are that:
    1. constraints and complements are replaced by explicit constraints,
    2. constraints of the containing node are also returned.

  - Methods of class Implicit that use member rhs_ have been made deprecated.

  - when inserting them. Throw if they are.
  - Add a test.

  to comply with modification in hpp-constraints.

  This fixes a bug due to numerical approximation. In some cases, an explicit
  constraint of the path is satisfied for a configuration, but the constraint
  of the node that is supposed to contain the path constraint is not satisfied.

  RelativeTransformation -> RelativeTransformationSE3 with mask.

  Replace deprecated Path::operator() by method eval.

  Replace deprecated Path::operator() by method eval.

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