Updating interfaces and dataprojection

Interfaces
==========
Updated InterfacePointsConnectivity_PointXiSet and added CMISSInterfacePointsConnectivity_PointXiGet
Removed coupledMeshUserElementNumber argument from these routines as ElementNumberSet already sets this.

Added temporary debug output to InterfacePointsConnectivity_DataReprojection, to be removed in a future commit.
Need to generalise routines related to how interface data points are projected onto the coupled mesh/bodies to define the interface connectivity. Three possibilities.
1) Embed interface datapoints on first coupled mesh surface, only project them to the second body (requires 1 projection - biased)
2) Embed interface datapoints on second coupled mesh surface, only project them to the first body (requires 1 projection - biased)
3) Embed interface datapoints in the interface geometric field project to bouth copuled mesh/bodies (requires 2 projection and updating of interface geomtric field)
2 is currently being used.

Allowed the same setup to be used for both INTERFACE_CONDITION_LAGRANGE_MULTIPLIERS_METHOD and INTERFACE_CONDITION_PENALTY_METHOD in:
INTERFACE_CONDITION_RESIDUAL_EVALUATE
INTERFACE_MAPPING_MATRICES_COEFFS_SET
INTERFACE_MAPPING_MATRICES_ROW_MESH_INDICES_SET

Dataprojection
==============
Added CMISSDataProjection_LabelSet/Get.
Updating the python bindings (required for dataprojection label set/get). The bindings exclude routines using varying_string parameters. The routine for searching and excluding such routines needed to be updated to also handle library calls such as CMISSDataProjection_LabelSetVSRegionNumber, CMISSDataProjection_LabelSetVSInterfaceNumber with were specific to an interface or region.
Updated convergence criteria for dataprojections

Tracker Item 1999,2271,2000