Use J2V8 with Node.js v8.x

@matiwinnetou @aschrijver @irbull

I create this issue to move the discussion about building J2V8 with Node.js v8.x over from [#327](https://github.com/eclipsesource/J2V8/pull/327#issuecomment-322931893)
(and to avoid potential duplicate efforts)

> With the tests in `v8/debug/` disabled and the additions from @matiwinnetou I was now able to build & run tests successfully for Node.js v8.2.1 on the marked platforms below
>
> By looking into [android-configure](https://github.com/nodejs/node/blob/master/android-configure) and the [Android NDK docs](https://developer.android.com/ndk/guides/standalone_toolchain.html#creating_the_toolchain) I hope it will be not too hard to get Android working also 🤞

(Android needs fixing, see [this](https://github.com/android-ndk/ndk/issues/82#issuecomment-321799310))

Platform
NJS Version
Build
Tests


Android x86
8.2.1
fails
-


8.4.0
✓
some tests ok, some crash
(same behavior as in 7.4.0)


Android ARM
8.2.1
TBD
TBD


8.4.0
TBD
TBD


Alpine Linux
8.2.1
✓
all ok


8.4.0
✓
some tests ok
some crash the JVM


Linux
8.2.1
✓
all ok


8.4.0
✓
some tests ok
some crash the JVM


Mac OS
8.2.1
✓
all ok


8.4.0
✓
some tests ok
some crash the JVM


Windows
8.2.1
✓
all ok


8.4.0
✓
all ok