Add floating point version of std::find
Add exact solution for simple case

* and incorporate into the implicit llg driver code
Modify polynomial interpolation for derivatives at input points

* Basic algorithm is numerically unstable there.

* But it's mathematically ok so just implement it differently

* Seems to improve the accuracy of midpoint methods error estimates
Add code for plotting error and dt vs time
Some new parameter sets, nothing interesting...
Update .gitignore

* Ignore entire experiments folder, should only contain data now...
Add cubeoid meshes
Exclude dummy error norms of "-1" from final outputs

* It's the the dummy no-error-norm exists magic number