explain With expressions
change `bla` to `bla.get()`

This allows distinguishing between

    Foo.Bar() = 2
    =>
    ...dot("Bar").let(2)

and

    Foo.Bar()
    =>
    ...dot("Bar").get()

(`=>` means "compiles to")
[14 Expression tests failed] `ns.dot` => `ns.get`

also stop splitting methods from callee (because of `this` problem)
[expr passed, 12 mod failed] `ns.dot` => `ns.get`

In the process undid some of `obj` changes made in 98d3793833ed
[39 mod tests failed] start ns.get change in mods
[13 mod tests failed] go on ns.get change in mods
[1 mod test failed] go on ns.get change in mods
[all test ok] `ns.dot` => `ns.get`
document VBObject/Attribute
remove nsObject and nsFunction
test VBObject with doctest