Make aevol 6 run on macOS

See merge request aevol/aevol!2

This commit adds asserts to ensure that the preconditions on
the points_ list are met when calling the function, namely:
- the list has at least two elements
- the first and last element are at abscissas X_MIN and X_MAX

Moreover, this commit moves the (p != points_.begin()) check
out of the if clause, and into an assert as well.

This ensures that if a bug happens here again, we will catch
it instead of sweeping it under the rug.

Théotime Grohens authored 5 years ago and David Parsons committed 5 years ago

The Fuzzy::clear() function completely discarded the points_ list,
but was supposed to reset it to its initial state with two
points at (X_MIN, 0.0) and (X_MAX, 0.0).

This commit fixes the function.

This commits adds the build/ folder from CMake and new post-treatment
executable files to the .gitignore file.

This commit updates the CMakeLists files by adding support for OpenMP
on macOS, and resolves a compile error in the SFMT build.