[icedtea-web] Idea - do not start ITW applets automatically

[helpcrypto helpcrypto]

> I am unsure as to how worthy this will be, given that Firefox
> plans to implement something similar[1] and Chrome already having this
> feature[2].

Didnt think about that, altought I see it everyday!.
We could implement that for unsafe browsers (ie: browsers that doesnt
have that security feature), and the problem will be to determine
which browser running, or if the browser has that feature.

Thanks for the usefull hint, Saad.