Derive Serialize, Deserialize for wrapper types

This crate provides several custom derives that provide implementations of serde's Serialize and Deserialize traits for wrapper types, as well as Deserialize implementations that perform some validation.

Sometimes you have a single-field type

```rust

[derive(DeserializeFrom, FromInner, IntoInner, SerializeInto)]

struct Contact { email: String, } ```

which you want to serialize and deserialize as a string instead of a struct, e.g. you want its JSON representation to just be ""user@domain.com"" instead of "{ "email": "user@domain.com" }". The above derive attribute creates Serialize and Deserialize implementations for that purpose, as well as Into and From implementations to convert between String and Contact.

Another example is a validated wrapper type like

```rust

[derive(DeserializeTryFrom)]

struct Email(String); ```

that should never be instantianted with a string that doesn't represent a valid email address. If you implement Email: TryFrom<String> using the try_from crate, such that conversion fails for invalid addresses, the derived Deserialize will also fail if the string is in the wrong format.