Add /lmgtfy and /lmbtfy commands

`/lmgtfy SignalR Documentation` becomes:
![lmstfyscreenshot](https://cloud.githubusercontent.com/assets/1687386/3526921/2f4c5274-0780-11e4-9298-44a41efc5f28.png)
Your call: maybe share the "A search query is required" resource text between both lmgtfy and lmbtfy when fixing this up.