Add flexibility to define user-level default configuration settings
Add facility to accept some sort of rc-type file/environment variables/etc, so that default values in the session file can be defined at a beyond-session file level -- especially useful in non-academic setting for e.g.:
- Smoothing with SVV (IncNavierStokesSolver)
- Choices of preconditioners and solver tolerances
- Turning off backup files (superceding #209 (closed))
- The feature might also provide added suggestions to the user for things that do not make sense or should instead be done (use of certain filters etc). This would fall also under the scope of improving usability of the whole codebase.
Things to think about:
- What mechanism do we use? rc files, xml-based or something else?
- How to make it solver-aware? For some solvers it may not be desirable to change the default behaviour.