Implement Wofram|Alpha lookup command

[FastLizard4]

Technically a reimplementation of a HAL-9001 command, though we won't be using the same method.

Implement a command to look things up using Wolfram|Alpha, but using the proper WA API instead of whatever (probably against WA's ToS) method HAL-9001 was using. Will require an API key and a rate limiter similar to the weather command since free API keys only allow 2000 calls per month.