Feature/nonconformal

Implementation

This adds non-conformal support. Full 3D and parallel are supported. Majority of implementation is in SpatialDomains/Movement folder and MultiRegions/AssemblyMap/InterfaceMapDG. See user guide additions for description & follow interpolation method here A comparison of interpolation techniques for non-conformal high-order discontinuous Galerkin methods.

Also includes:

• Barycentric derivative interpolation, see Fast Barycentric-Based Evaluation Over Spectral/hp Elements using PhysEvaluate overloading
• Some new MPI functions & some DG trace exchange improvements in parallel
• Some geom ID <-> trace ID/object functions in ExpList
• Multi-domain input/output for Nekpp files
• Multi-domain input/output for HDF5 files, bumped FORMAT_VERSION to 2 to maintain backwards compatibility
• New filter to calculate the integral of a variable on a mesh composite ---> Splitted into separate MR (!1409 (merged)) by @mlahooti
• Use the DisContField copy constructor in EquationSystem if variable has same expansion infos
• Improvements to IsentropicVortex equation system allowing for altering parameters via session file
• Update ExtractSurface2DCFS to use boost program options ---> Splited into separate MR (!1407 (merged)) by @mlahooti
• Tidied up LocalRegions and StdRegions expansions, removing redundant ''const'', adding override/final keywords etc...
• Removed unused variables that were giving warnings on latest Apple Clang
• Removed default copy constructors that were giving warnings on latest Apple Clang
• Added cmake-build-* to .gitignore for CLion build directories ---> Splitted into separate MR (!1405 (merged)) by @mlahooti
• Change deprecated ''sprintf'' to ''snprintf'' ---> Splitted into separate MR (!1406 (merged)) by @mlahooti
• Fixed the comments in VmathArray for function Vvtvvtp ---> Splitted into separate MR (!1408 (merged)) by @mlahooti