Mesh resolution at select points

[ccluri]

Refine meshes at selected points with different charateristic length compared to others.

Also refine mesh to finer resolution in general

[ccluri]

https://github.com/ccluri/leadfield_atlas/blob/ffeb132cd34010e9fc217af0a1e301336bfa0b85/mesh/setup_refined.geo#L105-L121

Done!

[ccluri]

Here the first 105-108 show how to increase resolution along a surface - I use this to increase the mesh resolution where the grounding electrode is.

Same thing but along a line is shown in lines 110-117 - a dipole where we need increased resolution.