Adds search tree.
Adds search tree.
Exports search tree.
Allows different op for search and finds.
Merge branch 'search-tree' of github.com:evanrs/thin-tree into search-tree

Conflicts:
	src/search-tree.js
Splits preOrder functions to return all following or preceding nodes as well.
Removes most functions, keeps find and search, adds lodash sugar off of _ property.
Add parents in addChild method.
Isolates lodash sugar methods.
Merge pull request #5 from evanrs/search-tree

Search tree