= can: don't close connection with chunkless streaming and explicit Content-Length, fixes #783

Connection headers are now only rendered if needed for the
protocol version, i.e. `Connection: close` only in HTTP/1.1 and
`Connection: keep-alive` only in HTTP/1.0.
= docs: add missing links to new directives in alphabetical list, refs #812
Merge pull request #802 from jrudolph/i/783-dont-close-with-explicit-content-length

= can: don't close connection with chunkless streaming and explicit Content-Length, fixes #783
= routing: better failure msg when binding in SimpleRoutingApp.startServer fails, fixes #819
+ http: Add model for `Link` header

This adds basic support for the Link header as described by RFC5988, Section 5:
http://tools.ietf.org/html/rfc5988#section-5

Multiple link-values are supported, but of the link-params only the rel, title, and anchor params are supported.
= http: ignore additional `rel` LinkParams after the first, refs: #609
= http: support parsing of full ISO8601 strings

The new implementation of spray.http.DateTime.fromIsoDateTimeString now
also supports strings in format `yyyy-mm-ddThh:mm:ss.123456Z`.
= httpx: allow UrlEncodedFormDataUnmarshaller to extract duplicate fields, fixes #823
Merge pull request #821 from jrudolph/i/819-SimpleRoutingApp-error-reporting

= routing: better failure msg when binding in SimpleRoutingApp.startServer fails, fixes #819
+ http: add model for conditional headers
`If-(None-)-Match`
`If-(Un)Modified-Since`
ETag
`Last-Modified`
+ routing: add `conditional` directive
+ routing: add `conditional` support to FileAndResourceDirectives
+ http: add model for `If-Range` header
= routing: extend `conditional` directive to also support `If-Range` header (test still missing)
= routing: minor fixes for FileAndResourceDirectives
! http, routing: minor refactoring of ETag matching
Merge pull request #797 from 2beaucoup/caching

Enable client caching (supercedes #776)
Merge pull request #824 from jrudolph/i/823-formDataMarshaller-throws-away-duplicates

= httpx: allow UrlEncodedFormDataUnmarshaller to extract duplicate fields, fixes #823
= io: drop exception (debug logged) in SslTlsSupport during finishClose, fixes #823
= http: make comment more specific