Summary:
*Stack summary*: this stack refactors plugin management actions to perform them in a dispatcher rather than in the root reducer (store.tsx) as all of these actions has side effects. To do that, we store requested plugin management actions (install/update/uninstall, star/unstar) in a queue which is then handled by pluginManager dispatcher. This dispatcher then dispatches all required state updates.
*Diff summary*: implemented basic plugin action queue processing.
Reviewed By: mweststrate
Differential Revision: D26164945
fbshipit-source-id: 5d8ad9b4d7b1300e92883d24a71da9ca1f85b183
8efdde08c4