While using sed can be handy to use for a quick-fix, these instances accumulate, and can become unmaintainable. Not only that, but using sed isn't necessarily robust and it can fail silently. Most of our usage is also missing any documentation explaining why something is being done, when it should be updated/removed etc. Rather than relying on sed going forward, where possible, I've converted our sed usage into patches. These are easier to maintain, contain documentation, and should fail loudly when they don't apply. The remaining sed usage, (1 in miniupnpc, the rest in qt), are non-trivial to remove, as they are using build-time variables, or some input from the environment.
Backport of core PR19761, slightly updated to match our depends.
Depends on D7760.