Added linear constrains to boundary conditions (e.g. periodic boundary conditions).
Added symmetric skyline support for assemblyoperation with rows and colums location numbers, build internal structure method now supporting active boundary conditions reporting multiple allocation blocks.
Optimized linearconstraintbc implementation using block assembly, added saving and restoring context methods
Additional documentation of ActiveBoundaryCondition::giveLocationArrays method
Improving flexibility of linear constraint bc: configurable characteristic components where contribution goes
Fixing incorrect assembly of lower triangular entries in Skyline. Also fixing linear_constraint_1 test.
Adding support for active boundary conditions in unsymmetric skyline (buildInternalStructure).
Forcing allocation of diagonal entry (required by some sparse matrx implementations).
CompCol sparse matrix made aware of active boundary conditions.
DynCompCol sparse matrix made aware of active boundary conditions.
DynCompRow sparse matrix made aware of active boundary conditions.
SymCompCol sparse matrix made aware of active boundary conditions.
DSS sparse matrix made aware of active boundary conditions.
Added documentation of linear constraint bc into oofem input manual
Fixing bug in linear contraint bc for multiple DOFs
Added test on periodic boundary condition.
Fixing number of spatial dimensions in computeWeightFunction
Fixing yet another assumed number of spatial dimensions in computeWeightFunction
Fixed bug in FloatMatrix :: solveForRhs
Merge branch 'XFEMDevelopment' of github.com:JimBrouzoulis/OOFEM_Jim

Conflicts:
	src/oofemlib/xfem/enrichmentitem.C
	src/oofemlib/xfem/enrichmentitem.h