Document 'errors' about solc-js

[chevdor]

I will publish a commit in a second about that one.
btw: I totally agree!

[chevdor]

Houston, we have a problem!
I do not want to change the tests without discussing a bit further the reason for them to specifically state that the compilation should not produce any output:

See https://github.com/ethereum/solc-js/blob/master/test/cli.js#L24 for instance:

 t.test('--bin', function (st) {
    var spt = spawn(st, './solcjs --bin test/DAO/Token.sol');
    spt.stderr.empty();
    spt.stdout.empty();        <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    spt.succeeds();
    spt.end();
  });

It especially says that the output should be empty. So my fix in 990e2f5 break those tests.

I would ask someone to confirm that this part of the test can and should be remove, then I am happy to do so.

[chevdor]

See #61