AquaVM panic handler

[mikevoronov]

At the moment AquaVM uses the abort panic handler, that doesn't provide any unwind actions in case of panic. Among other things it leads to persist already loaded data into the interpreter, since desctructors wouldn't be called. In a situation when memory growing failed since docker limits with panic, it leads interpreter to be out of serivce and unability to handle other incoming requests.

This one is on of issues of #141.

Using unwind panic hadlers will require more computation effort, but in future we could overcome it by run interpreter with a fresh memory every time, since it's stateless. But this change would require a lot of work on the Marine side.

[mikevoronov]

I think that we should enable debug info (https://github.com/fluencelabs/aquavm/blob/master/Cargo.toml#L22) in the interpreter at least for a while, because now it's in the actively development stage.