autopopulate *available-disassemblers* and autoload chosen disassemblers

[alanruttenberg]

No description provided.

[easye]

Chicken and egg: such a probe should perhaps be defined for javap here, and then modified on the load of the abcl-introspect package.

[alanruttenberg]

Your call. I think it just works whether abcl-introspect is there or not. If the disassemblers are somewhere else then you have to manually load them anyways.