= io: optimize BackPressureHandling: keep track of length instead of calling Queue.length
= io: BackPressureHandling: make sure Acks never slip through to the pipeline
= docs: extract signature lines with `includecode`

by matching `def <snippet>` up to (but not including) the trailing `=`
= docs: document `headerValueByName` as an example for documenting other directives
= build: update to sbt 0.12.4-RC3

Performance of (cold) sbt compilation for Scala != 2.9.2 was slow. This
should improve the speed of travis builds.

See
https://groups.google.com/forum/#!topic/simple-build-tool/HMjm3jpHc6Y
Merge pull request #341 from spray/feature/document-directives-stub

Directive documentation example
Merge pull request #343 from jrudolph/wip/upgrade-to-sbt-0.12.3-RC3

= build: update to sbt 0.12.4-RC3
! testkit: small clean-up, remove duplication with httpx RequestBuilding

This change removes the `pimpHttpRequestWithTildeArrow` method from the RouteTest trait
and brings the previously `private` TildeArrow class and object into scope. The latter
allows for explicit (manual) provision of `~>` implicits in order to simplify diagnosis of
implicits resolution issues.
= build: upgrade sbt-revolver and enable example server projects to use it
Merge pull request #347 from jrudolph/wip/new-revolver

= build: upgrade sbt-revolver and enable example server projects to use it
= routing: fix PathMatcher '|' not working between non-identical PathMatcher types, fixes #344
Merge pull request #345 from spray/ticket/334

= routing: fix PathMatcher '|' not working between non-identical PathMatcher types, fixes #344
= sbt: upgrade to SBT 0.12.4
= can: fix custom ClientSSLEngineProvider not used by host-level client-side API
Merge pull request #328 from mpilquist/client-ssl

= Fix bug where custom ClientSSLEngineProvider is not propagated to HttpHostConnectionSlot
= docs: amend commit msg policy with exception for merge commits
! routing: move `UserPassAuthenticator.cached` to `CachedUserPassAuthenticator.apply`, fixes #352

Because `UserPassAuthenticator.cached` relies on a spray-caching Cache even code not using this method
(but simply other `UserPassAuthenticator` methods like `apply` or `fromConfig`) must have spray-caching
on the classpath in order to avoid a `bad symbolic reference` compiler error.
This patch moves the `cached` method into a dedicated object thereby freeing up `UserPassAuthenticator`
from the dependency on the spray-caching module.
Merge pull request #353 from spray/ticket/352

routing: move `UserPassAuthenticator.cached` to `CachedUserPassAuthenticator.apply`, fixes #352
! http: make only standard charsets available as constants, fixes #340

Only standard charsets are known to be available on all Java platforms.
If another one was missing, initialization fatally aborted. Constants
for others charsets can still be retrieved from the registry but can't
be supplied as constants as those may not be available.

Another bug was fixed here: the 'ISO-8859-10' charset was wrongly registered
as 'ISO-8859-1'.
Merge pull request #354 from jrudolph/wip/fix-missing-charsets

! http: make only standard charsets available as constants, fixes #340