Implement contains and doesNotContain assertions for list types

[sabhiram]

1. The int[], uint[], bytes32[] and address[] types now have
   contains and doesNotContain helpers.
2. A lot of code in there is boilerplate - should we autogenerate this?
   This would make allowances to have helpers for more specific
   fixed-size byte arrays like bytesN[].

[gnidan]

Hi @sabhiram, thanks for this!

This is slated to be released in v4.0.7 (in two patch releases).

Everything looks great, implementation-wise, but I'd still like to verify that we're not making Assert.sol too costly to deploy (plus any other possible risks that come with the territory).

[sabhiram]

Yes totally, as I started adding functions I started to realize the bloat that it would add to day-to-day development.

I need to understand a bit more about how solc compiles its code and how expensive things like "inlining" and such are for the compiler. Perhaps we can get cute with some of the very redundant functions?

Would also be nice if there was some pre-process step that enabled only the asserts that were required (what if we broke it into N number of files?) - Probably a bad idea, but just throwing it out there. Very new to solidity and truffle, please excuse my eager ignorance :)