Small changes to micromag element dependencies

* Move dshape_dtest into MicromagEquations
  There was no need for it to ever be in the geometry dependant elements.

* Move interpolated_dmdx_micromag to .cc file
  So that it can use MMInterpolator (which is declared after
  MicromagEquations).

* Remove include of flux header from micromagnetics_element
  Didn't need it, was creating strange circular dependcies.

* Start to remove templating from MicromagFluxElement
  Don't really need to do this yet because we don't use it unless we have
  surface anisotropy. Not worrying about details like that yet!
Make Flux_mesh_factory private + add access functions
Add a "standard parameter sweep argument option

and use this instead of 'midpoint_comparisons', since many of the parameter
 sweeps are not midpoint related.
Remove all oomph-lib headers from generate tetgen sphere input

* They weren't needed
* Makes the code more general
* Makes the compiled code MUCH smaller (it was HUGE before!)
Fidle with sphere mesh generation file names

* Before it would make files with indicies 2-6, now 1-6 (same as other meshes)
Finish off "dynamicising" semi implicit problems
Small fixes and updates to get the self tests working again