Core.mimmo object narrow band search.ra

[roccoarpa]

General rework of Propagator classes to clean up algorithms and usage.

• Modification on interfaces to deal with issue #111
• Temporary fix of point communications in communicatePointGhost data (perform twice the communication to fix data values on multiple-rank shared nodes).
• Added NarrowBand control (alternative to Damping) to relax laplace propagation near boundaries.

Update MimmoObject interfaces, adding new methods (narrow band evaluation on points, get ids of cells and vertices directly to the object, etc...) Fix setPartitioned method, which now internally builds adjacencies required by biptit::PatchKernel partition method.

[edoardolombardi]

Updated pull request:

• removed temporary double communication to fix data values on multiple-rank shared nodes
• fixed ghost points exchange lists generation to deal with issue #135