Allow accelerator ids for "toTop", "toBottom" in user content script pages... useful for user-content arrows without having to build a user.js to do this for anyone.

Mentioned in https://github.com/OpenUserJs/OpenUserJS.org/pull/129#issuecomment-45580636
Merge pull request #144 from Martii/acceleratorIds

Allow accelerator ids for "toTop", "toBottom" in user content script pag...