Problem: The style guide currently recommends having a `default:` case for switch statements that are not conditional on an enumerated value. Additionally, it recommends using `assert(false)` if `default:` is unreachable. This is problematic because `assert()` only runs on debug builds, which may lead to confusing breakages in release builds. Moreover, this suggestion is followed nowhere in the C code and `abort()` is used everywhere instead.
Solution: Suggest using `abort()` instead of `assert(false)`, that way the program always terminates if a logically unreachable case is reached.
Uncrustify and clang-format are already both excellent at ordering
includes; this isn't something we need to check for ourselves. Also
remove the section on include order in the dev-style documentation.
