RFC: Use "throw" with a specific exception instead of "error()"

[kmsquire]

Cleaning up error functions.

In cases where the correct exception seemed ambiguous (e.g., pop! on an empty Deque), I followed conventions in Base.

[kmsquire]

Will merge tomorrow if there are no comments.

[DanielArndt]

@kmsquire really quick rebase needed here (there's a small conflict with you adding a Base.Test import, and pr #172 removed the imports) which I can do if you wouldn't mind that I force push over your branch (Or if you have a few minutes quickly do it yourself).

[kmsquire]

If you wouldn't mind doing that and merging, that would be great!

[kmsquire]

Thanks!