This commit changes the way Rocket parses form items. In particular, it now
(liberally) validates form strings, returning a Bad Request on malformed inputs
and Unprocessable Entity on bad parses.
The 'FormItems' iterator was modified to accomodate this. The iterator is now
initialized using 'from': 'FormItems::from(form_string)'. The iterator can be
queried to check for a complete parse using either 'completed()' or
'exhausted()', the latter of which will consume valid keys/values and return
true only if the entire string was consumed.
The 'FromForm' trait now takes a mutable borrow to a 'FormItems' iterator.
The 'Form' and 'FormForm' implementation for 'Form' were modified to use the new
iterfaces and check for 'exhausted' after a parse, returning a Bad Request error
if the iterator cannot be exhausted.
Resolves#46.
This commit changes the routing algorithm. In particular, it enforces
precise matching of formats. With this change, a route with a specified
format only matches requests that have the same format specified. A
route with no format specified matches any request's format. This is
contrast to the previous behavior, where a route without a specified
format would match requests regardless of their format or whether one
was specified.
This commit also changes the following:
* The return type of the 'content_type' method of 'Request' is now
'Option<ContentType>'.
* The 'ContentType' request guard forwards when the request has no
specified ContentType.
* The 'add_header' and 'replace_header' methods take the header
argument generically.
Closes#120.
A few interesting notes on this breakage:
* `Cookie` how has a lifetime. It should be `'static'` everywhere.
* The `SetCookie` header is no longer reexported.
* Instead, `Cookie` implements `Into<Header>` for Set-Cookie.