Avoid known Erlang incompatibility

In erlang,

1> 123456789123456789123456789 bsr 123456789123456789123456789.
123456789123456789123456789

In Erjang, … more correctly

1> 123456789123456789123456789 bsr 123456789123456789123456789.
0
Be less verbose when halting
Fix bug in arith_test (didn't compile)
Run with node name @127.0.0.1 rather than DNS