Implemented Copy.

Implemented Copy for ParseError, ParseErrorKind, RecordTerminator and
QuoteStyle.

This fixes an issue with the latest version of rust (rustc 0.13.0-dev (8fbfa66b4 2014-12-09 21:56:13 +0000)) which causes:
```
src/reader.rs:649:32 649:36 error:  cannot move out of dereference of `&mut`-pointer
```