Amend RFC #195 to clarify associated lifetime syntax

[apasel422]

Per rust-lang/rust#17842, this will probably turn all lifetime identifiers into lifetime paths preceded by '. As a concrete example:

struct Bar<'r>(...);

trait Foo {
    lifetime 'a;
    lifetime 'b: 'Self::a = 'Self::a;

    fn foo(&'Self::a self) -> Bar<'Self::b>;
}

impl<'a> Foo for &'a i32 {
    lifetime 'a = 'a;
    lifetime 'b = 'static;

    fn foo(&'a self) -> Bar<'static> { ... }
}

fn baz<'b, F, G>(f: &F, g: &G) where
    F: Foo,
    G: Foo<'a = 'F::a>,
    'F::a: 'b,
{
...
}

CC @aturon.

[burdges]

I take it nothing happened here yet? I presume the issues are similar to -> impl Trait in traits?