Add support for pure implicit problems in param sweep and parse scripts
Improve multi mesh support

* Move multi mesh factories up into main factories namespace

* Add support to (implicit) llg mesh construction

* Use generic has_prefix and rest_of_name functions where possible
Add option to use gmres<SumOfMatrices> as the solver
Use intp. to get div m in llg residuals
Add option to clean out old results in parameter sweep script
Add factories and cli for meshes with many sub meshes on an array