Drop the dependency of paste

[cathay4t]

Paste is unmaintained which will cause cargo audit or cargo deny warnings.

Choices are:

1. Copy paste code into netlink-packet-core-derive crate.
2. Drop buffer!() and use bincode or self cooked decoder/encoder.

[qinqon]

@cathay4t I am going to fix this issue using option 1 so we copy the crate into this one.

btw looks like I need to create a new crate since proc-macros must be in a separate crate

[cathay4t]

The downside of option 1) is need new crate.

For option 2: I am playing with self buffer parsing in nispor/mozim#59 . It looks good.

[qinqon]

The downside of option 1) is need new crate.

For option 2: I am playing with self buffer parsing in nispor/mozim#59 . It looks good.

Ok I will drop my PR then.

[cathay4t]

I noticed there are panic-able code in buffer!(). So I am in favor of replace buffer! with self-parsing struct now. It will be massive work. Let me finish the first step on RouteNetlinkMessageBuffer first.