Prevent duplicate tree nodes, fix sorting error

[jasonsanjose]

@iwehrman

[iwehrman]

Just did a New File command in the root directory and got this:

[iwehrman]

And when I right clicked on a file (in the example below, .travis.yml) and executed New File it ended up like this:

[jasonsanjose]

That first dev tools screenshot looks like stale code, doesn't match my branch: https://github.com/adobe/brackets/pull/6468/files#diff-58c1993f5c3fd9299086f7d0519a643fR487.

[iwehrman]

I double checked that I'm on your branch and it's up-to-date. The sort ordering is off:

[iwehrman]

I'm also still seeing the thing where a new file gets created inside an existing file.

[jasonsanjose]

@iwehrman Fixes pushed. I can't reproduce the sort issues anymore, but I didn't make any changes there since my first commit. I'll keep trying.

[iwehrman]

Finally, all of the bugs in the file tree are gone! 👏