Test Static Function ID using DWARF

The title says it all. For some reason I couldn't get r2 to work, even after quite a bit of tinkering. For that reason it only checks the builtin function identification. If r2 works for you, feel free to add it into the list of engines near the top.

Also check out --profile at some point if profiling is your thing. It might make debugging performance issues easier. Builtin seemed pretty fast but it will be interesting to see its performance on larger test cases (real software?)

Another note: this uses DWARF, so it doesn't really capture all of the functions in the binary, just the ones that are compiled in with debug info. Depending on your opinion, this might be better as those are probably the functions you really want to identify.
if self.debug >= 1