[Amibe] Add singularity order 'alpha' for analytic metric
[Amibe] Cosmetics: update help on refine.py, remesh.py and remeshSingularity.py
[Amibe] Update example of RemeshMetric in python script for the cube model problem

Modify analytic metric for a singularity in 1/r^alpha
[Amibe] Add numerical criterion and mixed metric in class RemeshMetric
[Amibe] Numeric metric: geometric interpolation on first interval
[Amibe] RemeshSingularity: increase number of smoothing iterations
[Amibe] RemeshSingularity.py: better handle beams

- fix bug in arguments
- optionally remesh beams
- add a list of immutable groups
[Amibe] Update jython interfaces for amibe-unv converters