atom_to_binary/1 not accepted as auto-imported

[fowlay]

The erlang:atom_to_binary/1 function is auto-imported, but erlide flags it as "undefined function" if the erlang: qualification is omitted.

[vladdu]

Unfortunately, erlide has not been updated to suport recent Erlang releases, and I'm not really working with it anymore. This fix should be easy, but I can't promise when I will look at it... The problem is that the development environment for the erlide_kernel project is tricky to setup and I haven't touched it in 4 years. I am sorry about that.