feature/meshelements makeorder

This merge cleans up a lot of the code in NekMeshUtils/MeshElements. 
It also improves the MakeOrder routines to include CAD entities in the logic.

This depends on MR !697 

See merge request !698

feature/foundations_SPI

Adds symmetric positive integration system to elements with one or more triangular face (not tensor expansion).
This is built onto of dave's work on the new nodalutils so will need to be merged and checked after that.

See merge request !696

Fix bug in DG with hybrid meshes

This fixes a bug in AssemblyMapDG which causes simulations with hybrid meshes to fail.

See merge request !694

Fix to the regression test of the tutorial on integration (1 of 2)

Necessary fix for another MR in the tutorial submodule (same name).

Ready to merge.

See merge request !701

Extend ExtractDataToCoeffs to support basis interpolation for quads and hexes

This MR adds support to ExtractDataToCoeffs for interpolating between basis types. Presently, it's assumed in the code that the restart basis type is the same as the simulation type, which means that errors can be introduced when restarting simulations from different basis types. Since the most common use case is the quad and hex, where a nodal simulation might be used as a restart condition for a modal simulation (or vice versa), this MR implements this functionality only for these element types.

See merge request !682

Conflicts:
	CHANGELOG.md

Fix performance issue with IterativeFull solver.

Removes the request for Robin BC info every iteration of the CG solver.

See merge request !693

Fix issue with output in parallel

This fixes an issue some people have experienced where only part of the files in an fld are written in parallel.

See merge request !699

Feature/insert new logic

Adds non-conforming logic to the high-order surface insert routine to get it to work with symmetry planes from star-ccm+ meshes.
It also clears up a couple of bugs which were introduced in previous merges because buildbot didnt test NEKTAR_USE_MESHGEN, also fixes the associated tests.

See merge request !700