Document private vars

I don't know of a good way to protect private vars from being overwritten. I know @toddself accidentally ran into the situation where he overwrote a private var. Perhaps we could add a list of private vars not to overwrite.

```js
this._hasWindow = typeof window !== 'undefined'
this._id = null // represents the id of the root node
this._ncID = null // internal nanocomponent id
this._proxy = null
this._loaded = false // Used to debounce on-load when child-reordering
this._rootNodeName = null
this._name = name || 'nanocomponent'
this._arguments = []

this._handleLoad = this._handleLoad.bind(this)
this._handleUnload = this._handleUnload.bind(this)
```

The issue names no source file or test; start by locating the component initialization that assigns the listed private variables. Determine the intended behavior for preventing those variables from being overwritten, then document or test the agreed protection rules so accidental overwrites are covered.

Written by the indexing model from the issue text.