This is a breaking change.
This commit introduces `RawStr` to forms. In particular, after this
commit, the `&str` type no longer implements `FromFormValue`, and so it
cannot be used as a field in forms. Instad, the `&RawStr` can be used.
The `FormItems` iterator now returns an `(&RawStr, &RawStr)` pair.
This is a (minor) breaking change. If `rocket.launch()` is the last expression
in a function, the return type will change from `()` to `LaunchError`. A simple
workaround that preserves the previous functionality is to simply add a
semicolon after `launch()`: `rocket.launch();`.
resolves#34
* All From* trait methods are now named like the trait.
* All From* traits have an associated Error type.
* Document all of the `form` module.
* Add codegen tests for auto-derived forms.
* The param parsing traits now live under Request.
Sergio Benitez
Matt McCoy