Add menu items to Sublime to open settings files
Add menu items to Sublime to open settings files

This is a common convention for Sublime Text plugins and will make it
easier to modify the settings that may be required to get ImportJS
working with Sublime Text.

For some reason if I put the preferences child above the tools child,
the tools menu item no longer shows up, but in this order things are
just fine. I wasn't able to determine why, so I'm just going to roll
with it.

Addresses #220 and #219

trotzig/import-js,trotzig/import-js,trotzig/import-js,Galooshi/import-js