Added Issues to dev tools (#2488)
Added Issues to dev tools (#2488)

* [dev-tools] Added Issues to dev tools

Issues are clearable persistent issues like the ones Doctor sends. This
adds them to GraphQLSchema, adds a store for them and adds client-side
support for removing them

* [dev-tools] Provide a default for sections on client, not server

* [dev-tools] Updated snapshots after rebasing

fbshipit-source-id: 6247b3e

exponentjs/exp