Show solcjs compilation flags information

[adria0]

There's a tuning about optimization loops in

https://github.com/trufflesuite/truffle-compile/blob/331809c73389f27f9dda40229061bb75b18f27ca/index.js#L70

but, since this modification it's not a default in solcjs, and it is not warned there's no way to verify the code in etherscan once deployed.

I sent a email to etherscan about supporting this compilation flag, too.

[tcoulter]

We'll add the default parameters to our documentation. We've created a ticket that will allow people to override the default compiler optimization setting. trufflesuite/truffle#486.

[tcoulter]

Thanks!