Merge pull request #5 from bgrins/patch1

Update README with instructions and markdown formatting
Remove redundant 'title' from resources.
Add an Open menu item.
Implement Save As
Add a file-picker module
Add missing file.
Move ownership of scratch and open stores to the Project.
CommonJS osfile.jsm.
Add a Project.resourceFor to reliably get a resource for a path.
Add some convenience methods for finding associated resources.
Add the necessary require to osfile.js
Implement Project.refresh()
Add an Itchpad.liveEditor() convenience method.
Change ResourceMap to use the project instead of its own set of stores.
Move responsibility for indexing from the stores to the project.
Some basic path matching smarts for search.
Add fuzzy searching to the project index.
Maintain the project index in the project.
Add a method that annotates a search string with the pieces that match.
Add a score function to path matching.