[Rebased] Radially aligned annulus and icosahedral shell maps.
Rebased !829 (closed) on master after merging !828 (merged).
Re-introduced from 7bc4be0b and parents (see !792 (closed)).
Opposed to their "unaligned" counterparts, the new maps align micro-vertices radially along rays from the origin.
These new maps are not well tested in combination with operators, but the forward mapping should be working and usable with the implementation of parametric maps via the MicroMesh class (example in apps/show_mesh.cpp
).