Update numbering when a new mesh and solution is read

[rw-anderson]

Fix to update numberings when a new mesh and solution is read in. This is important, for example, when the new mesh is adaptively refined.

[tzanio]

Is this ready-for-review @rw-anderson ?

[tzanio]

Thanks Bob!

[rw-anderson]

An unfortunate side effect of this change is that the warning about rendering for large meshes is spit out every time a new mesh and solution is read in.
I suppose with the work that's been done lately, I should test to make sure that's still a performance issue.
And secondly, if it still is, to only emit the warning when the numbering is requested with a keypress, not every time it goes through the pre-computation phase, so it doesn't pollute the output message space.

[publixsubfan]

With the shader-based renderer (macOS, Linux, and WebGL clients), there shouldn't be a significant performance impact; we upload the text as a vertex buffer which is then transformed to the correct position inside the shader. There may be a performance impact with the legacy OpenGL renderer (remote X11 or with -oldgl switch), since we have to issue draw calls for each triangle in the text.

That being said, drawing triangles should be much faster than drawing bitmaps, which was the main performance issue with the old numbering stuff.

[tzanio]

@rw-anderson can you test and let us know how best to resolve #188 (comment)?

I'll hold on merging this until then.

[tzanio]

@rw-anderson any progress?

(We want to have most of the glvis-4.1 PRs merged by the end of this week)

[rw-anderson]

Sorry I haven't looked at this again yet. I should be able to take a look on Friday.

[tzanio]

Friday is OK, thanks!

[rw-anderson]

I tested it and performance seems fine with the latest code, so I'm just removing the mesh size limitation.