ConnectionStringBuilder and Enum/Delegate cleanup

I've started with the codebase cleanup. As a lot of the code is a bit chaotic due to all the changes done over the past years by various authors, it's best to clean the stuff up a bit, weed out dead code and the like, restructure files, make everything look the same and professional and more predictable, so it's easier to understand when reading the code. 

I've started with the connectionstring builder. I had cleaned up the connection class as well, but that was in v2.2, and as it changed a lot in v3 branch, I'll re-do that one later. 

(all tests pass)
It could be argued that static methods vs. instance methods read and manipulate shared vs. non-shared state, and because of this they're largely analogous to static fields vs. instance fields. Properties are even closer to methods since, well, they really are methods (contain arbitrary code).

But no need to spend more time on this, it doesn't bother me that much or anything, was just interested.