Resolve all warnings we get when compiling

[brandonpaiz]

This makes it hard to see actual complication errors. For each type of warning, we should either

1. Change build config so these warnings are silenced
2. Actually fix the warnings, then change the build config so that these warnings are marked as errors, meaning the code can't be merged in the first place

Each type of warning should be ignored or converted to an error on a case-by-case basis