Add App shortcuts

[cesquivias]

trafficstars

I added one static app shortcut to the bart map and the remaining are taken up by the user's saved trips. There's a limit of 6 app shortcuts so, at most, the top 5 saved station pairs are made into app shortcuts.

I'm no designer so unfortunately my app icons for the shortcuts are just basic menu icon images blown up.

[dougkeen]

Awesome... thanks for the submission! I'll take a look as soon as I get a minute (and fair warning, I might swap out some of those icon assets post-merge).

[cesquivias]

Please do 😉