The problem was that Location_traits is templated by Named Parameters, and
it is extremely unpractical to have to explicitly write the type (it's nested
classes all the way down).
Instead, we use template aliases for most types, and template by the field
type (FT) when necessary, which is much easier to write for the user.
Since template aliases cannot automatically deduce template parameters,
non-Doxygen versions of functions must be written without them
from time to time.
Other fixes:
- Simplify implementation of function 'random_location_halfedge'
- Don't initialize FTs from doubles
- Minor doc improvements
- reference to points when using VPMs