Adding Arg.Use<T>() to support catching and using arguments passed to calls
When creating copy of call spec that matches any args use method parameter type rather than spec type

Fixes issue #55.
Renaming Arg.Use to Arg.Capture and adding xml-doc comments for Arg methods.
Docs for Arg.Invoke and Arg.Capture, CI build links and acknowledging 7z library

Documenting Arg.Invoke and Arg.Capture.
Adding link to CI builds
Adding Codebetter-CI and Teamcity links to footer.
Adding 7-zip to acknowledgements.
Updating code extraction to support documenting standalone tests
  declared with [Test] attribute.
Updating changelog to include Arg.Capture().
Updating docs to show Arg.Is(predicate) behaviour when predicate throws
  and Arg.Any<T> behaviour with sub-types.
Renaming Arg.Capture to Arg.Do as per @AnthonyEgerton's advice.
Docs: Adding link to Arg.Do from When..Do docs. Adding docs for setting out/ref args.
Updating changelog for release 1.2.

Removing SL build from rakefile as it is not ready for release.
Updating BreakingChanges.txt for 1.2 release.
Adding SL40 to ALL build target so it is available from CI builds.
Updating to NuGet 1.5 release.
Updating download link on website to 1.2 ZIP.
Stop intercepting virtual member calls in ctors of substituted classes

Proxies created via CastleDynamicProxyFactory only start intercepting
  calls once proxy is created, so calls to virtuals made during ctor
  pass through without affecting nsubstitute.

  Calling virtual members from constructors is already known to have
  non-obvious results from .NET itself (http://msdn.microsoft.com/en-us/library/ms182331(v=VS.100).aspx),
  so this change is inline with general framework guidance.

Added StartIntercepting() method to CastleForwardingInterceptor.
Inlining CastleInterceptorFactory.
Closes #57.
Fixing typo in nuspec.
Update logic for running argument actions when argument is null

Checking argument type compatibility failed when null for reference
  types. Updated to treat null as compatible for ref types.
Closes #61.
Add System.ServiceModel reference and stop replicating ServiceContract (#60)

- Adding reference to System.ServiceModel for all build targets
- Adding ServiceContractAttribute to AttributesToAvoidReplicating used
    with Castle Dynamic Proxy.
Clearing unused pending call specs when new calls are received (#59)

Updating all routes other than RecordCallSpecificationRoute
  to clear any unused pending call specs. Pending call specs are
  only required for ResultSetter to use a call specification to set
  a result instead of the last call on the call stack. Every new call
  a substitute should be able to clear any unused call specs to later
  calls to Returns(...) don't get an old call spec.
Updating changelog with issues #59, #60, #61
Updating for 1.2.1 release

Bug fix release.
- Removing SL40 build from release
- Updating download link from docs
Adding back SL40 target so it is available from CI builds.
Attempting to add some thread safety to CallResults and CallStack (#62)

Using a substitute from multiple threads in production code can result
  in concurrent access to the backing collections of CallResults and
  CallStack. These are now backed with ConcurrentStack/Queue collections
  which seems to fix the problems reproduced in the MultipleThreads
  fixture.
Updated SL build to latest version.