Please change examples to `funnel`, not `new Funnel`

[alanhogan]

In short, documenting Funnel as a class is leading some devs to treat Funnel differently than other Broccoli and even Node modules. Look how Funnel sticks out like a sore thumb:

var mergeTrees = require('broccoli-merge-trees'),
    Funnel = require('broccoli-funnel'),
    concat = require('broccoli-concat'),
    path = require('path'),
    find = require('lodash/collection/find'),
    fs = require('fs');

If I made a brief PR to change example usages in README, would you accept it?

[rwjblue]

New should be used with all broccoli plugins. We are making this te default for all official plugins (and the vast majority of plugins work fine when used with new already).

[alanhogan]

Fine.