Add packagecontrol labels

[abathur]

• survey packagecontrol for any obvious related packages to see what labels, verbs, and nouns they use (labels: utilities, utils, project, workspace)

• brainstorm a bit about whether there are any good terms that aren't in use (other terms: session, group)

• Once this feels exhaustive, add the best few to the packagecontrol def (i.e. "labels": ["label1"],).