Mark outdated packages in the gutter

[insin]

Would it be possible to mark packages which need an update in the gutter so you don't have to hover over them to check?

[yavorsky]

@insin It's a good idea and I have some draft with this.
The only problem is that we need to send many requests to check all packages together. Some of the people don't want to have background requests, especially with slow internet connection (or even chargeable 3g with personal hotspot).

We can:

• Add boolean setting to enable this feature. But in some cases, I can forget to disable it when taking my laptop and go coding to park with personal hotspot.
• Check internet connection from plugin environment. (I dunno whether it's possible, but still worth trying)
• Add command Bump: Check all packages which would run all these checks manually.
• Create standalone server which accepts the request with an array of packages and respond with an array of versions. Pros are: 1 request, no need for json parsing, reasonably for a slow connection.

The last one seems the most reasonable to me.