This formats all copyright comments according to SPDX formatting guidelines.
Additionally, this resolves the remaining GPLv2 only licensed files by relicensing them to GPLv2.0-or-later.
Makes our error coverage a little more consistent across the board by
applying it to Linux side of things as well. This also makes it more
consistent with the warning settings in other libraries in the project.
This also updates httplib to 0.7.9, as there are several warning
cleanups made that allow us to enable several warnings as errors.
Allows reporting more cases where logic errors may exist, such as
implicit fallthrough cases, etc.
We currently ignore unused parameters, since we currently have many
cases where this is intentional (virtual interfaces).
While we're at it, we can also tidy up any existing code that causes
warnings. This also uncovered a few bugs as well.
