File browser

Compliment for auto complete for paths.

Currently if a modal is open and you open file browser (Edit Series) then the original modal is lost, I played around with restoring the original modal when the file browser is closed, but it isn't very smooth and causes issues with updating the input i the original modal. A second modal with a larger z-index would hide the original one, but we'd still need to make sure we're handling bootstrap events properly (clicking outside of the modal) so we don't kill both modals.
yeah, I really don't like it being mixed with files and dir. it feels too hackey, honestly I would prefer to have it even as a separate api call, or wrap the result and include the parent in the root something like this

```
{
   "parent" : "c:\",
   "files" : [],
   "folders" : [] 
}
```
where `root=undefined` means it's the root and there is no more.