Previously, LBJ was available:
– under stack_solve_algo=6 when neither block nor bytecode were present
– under stack_solve_algo=1 with either block or bytecode (but the documentation
was not making it clear that it was LBJ)
This commit merges the two values for the option, and makes them
interchangeable. LBJ should now be invoked with stack_solve_algo=1 (but
stack_solve_algo=6 is kept for compatibility, and is a synonymous).
It is now supported by the MATLAB editor (as of R2022a).
The old ASCII notation is left in some files that we copy as-is from other
sources (e.g. in the contrib/ and m4/ subdirectories).
The particles submodule is not updated at this point, because it is in an
inconsistent state.
[skip ci]