The tests for LINCS and SHAKE constraints.

The tests for LINCS and SHAKE constraints.

The tests for LINCS are first introduced,
SHAKE tests are migrated here from a separate
file.

The tests are performed on simple systems of two
to four bonds as well as on the peptide of three
amino acids. The tests ensure that the final length
of each constrain is equal to the target length.
For the peptide tests with HBonds and AllBonds
constrained, there is an additional check that
the final coordinates of all atoms correspond to the
reference set of values.

Free energy evaluation, virial and velocity constraints
are not yet tested.

Change-Id: Ic3a5c73a7e3223c0b7aafde9a0947e89e611f7b8