Wiretree 
Wiretree constructor
Creates new tree

Example:

```javascript
var Wiretree = require('wiretree');
var tree = new Wiretree( 'path/to/rootFolder');
```

@param  {String} folderPath path to root folder
function (rootPath) {
	// public properties
	this.plugins = {};
	this.mainTree = {};
	this.groups = {};
	this.resolved = false;
	if (rootPath) {
		if (typeof rootPath !== 'string') {
			throw new Error( 'Invalid rootPath parameter creating tree' );
		}
		this.rootPath = rootPath;
	} else {
		// no argument passed
		this.rootPath = '.';
	}
}