Add custom output support

i've added a third optional parameter: `out`.  when omitted, dependencies will be installed to `/components`.  when provided, dependencies will be installed to whatever the value of `out` may be.

this opens the api:

```js
install('/path/to/my-component', false, 'dependencies-of-my-component', function (err) {
  ...
})
```

in order to test, i've had to create `install-res-3`.  this is a copy of `install-res-*`, but with dependencies in `/deps` rather than `/components`.