Remove stuff we don't need or want

key maps, menus, and content
Instantiate a SmartTabsPaneView for each pane
Log pane events to console
Use consistent string quoting style
Unsubscribe on #remove
Change inline callbacks into explicit methods
Remove unneeded events
Open all new tabs into a preview tab

Doesn’t yet allow pinning so that it’s not a preview
Double click tab to un-preview it
Un-preview the previewTab after double clicking on an item in the tree
Don't null out previewItem unless the double clicked tab is a preview
Cleanup double click event
Merge branch 'initial-functionality'
Get active tab from event

Instead of item
Merge branch 'multi-pane-issues'
Listen for editor modification and un-preview the preview
Merge branch 'un-preview-when-modified'