(WIP) Open file in pending state on right arrow

[kuychaco]

addressed in #712

Currently the key-bindings are funky. I suspect I don't have the selectors quite right in tree-view.cson. Help figuring out what to do differently would be much appreciated 😄

Changed this:

'.tree-view':
    'right': 'tree-view:expand-directory'

to this:

'.tree-view .directory':
    'right': 'tree-view:expand-directory'

'.tree-view .file':
    'right': 'tree-view:open-pending-file'

Original key binding resolving:

New key binding resolving (note that both .tree-view .directory and .tree-view .file show up in both cases...):