Re-enable generation of surface meshes via CGAL.
Some formatting fixes.
More clean up.
Fix boost::shared_ptr casting to bool.
Coee fix in XMLLocalMeshSAX.cpp. Picked up in C++11 mode.
Add ImplicitSurface class.

Represents a surface via a function f(x) -> r, with the point y lying on the surface if f(y) = 0.

Requires a bounding sphere that bounds the surface.
Add SurfaceMeshGenerator class.
Move Point to dolfin/geometry.
Remove some SWIG generated files.
Fix for relocated Point code.
Update SWIG interface generation script.
Merge branch 'master' into garth/surface-mesh-generator
Merge branch 'master' into garth/surface-mesh-generator
Get basic CGAL implicit surface meshing working.
Work on CGAL mesh generation from implicit surfaces.
Testing surface mesh generation.
Add 'surface filtering to cope with generating open surfaces.
Merge branch 'master' into garth/surface-mesh-generator
Use surface test in more CGAL->DOLFIN mesh builders.
Merge branch 'master' into garth/surface-mesh-generator

Conflicts:
	cmake/scripts/generate-swig-interface
	dolfin/fem/DirichletBC.cpp
	dolfin/geometry/dolfin_geometry.h
	dolfin/io/XMLMesh.cpp
	dolfin/swig/geometry/pre.i