Binder/Examples contain hard-coded paths including outdated llvm version

[jwuttke]

examples/examples_struct/make_bindings_via_bash.sh, among other scripts, contains a hard coded path $PWD/../../build/llvm-4.0.0/build_4.0.0*/bin/binder. This looks pretty outdated, and for sure is a maintenance burden.

Decouple installation and use. Request that the executable binder be in PATH before the examples can be run. Replace the hard-coded path to the binder exutable by plain binder, nothing more.

[lyskov]

Sounds like a good idea to me, tagging @danpf who is author of this example.

@jwuttke right now we treat these examples more like "doc" then a code (ie we do not re-run them etc). But converting this to some sort of integration test (and possibly run them as part of CI) sounds great to me. PR to do so will certainly be welcome :)

[shakfu]

If anyone is interested I have a very simple working example here