add convertToOption to jsValue

[tmnd1991]

Why not adding a convertToOption[](or tryConvertTo[]) and a parseJsonOption, that doesn't throws a Exception (we all hate avoidable exceptions) but just returns None if the json string cannot be parsed or the jsValue cannot be converted?
I simply coded them in this gist (https://gist.github.com/tmnd1991/c740d2893d08dcf30110)
but it's not efficient at all ;\