Fixes #142 - Deploy the automatic build on Appveyor (#144)

* First configuration stub

* Get rid of the old winsw_cert.pfx references, adjust docs

* Fix the corrupted log4net reference, we use 2.0.3

* Generate stub SNK file

* Signing: Try full SDK path to generate SNKs

* Fix the path

* Signing: Sign all assemblies being packed into WinSW

* Tests: Try enabling tests

* Tests and artifacts: Use absolute paths

* Artifact path must be relative

* The test DLL is the NUnit one

* nunit-console does not require loggers

* NUnit: Try picking all DLLs in the output folder

* NUnit console: No wildcards

* Tests: Fix the test project to make it properly working with the new project structure

* Docs: Clarify the specifics of external extension usage

* Add AppVeyor badge to README.md

README.md

@@ -1,6 +1,8 @@
 winsw: Windows service wrapper in less restrictive license
 =========================
 
+[![Build status](https://ci.appveyor.com/api/projects/status/i94752yal9iy77in?svg=true)](https://ci.appveyor.com/project/oleg-nenashev/winsw)
+
 WinSW is an executable binary, which can be used to wrap and manage a custom process as a Windows service.
 Once you download the installation package, you can rename `winsw.exe` to any name, e.g. `myService.exe`.
 
@@ -65,6 +67,6 @@ New versions with fixes may be released on-demand.
 ### Build Environment
 
 * IDE: [Visual Studio Community 2013](http://www.visualstudio.com/en-us/news/vs2013-community-vs.aspx) (free for open-source projects)
-* winsw_cert.pfx should be available in the project's root
+* `winsw-key.snk` should be available in the project's root in order to build the executable
  * You can generate the certificate in "Project Settings/Signing"
  * The certificate is in <code>.gitignore</code> list. Please do not add it to the repository