Activate Strong-Name Signing

[cptjazz]

This PR adds a signing key and activates strong-name signing over all projects.
Closes #225

(The diff is flawed due to whitespace changes. The real action happens at lines 40 – 43.)

[sean-gilliam]

We should probably generate the key ourselves on the build server or ask the .NET Foundation to give us a key.
If it's like other crypto keys, then it seems wrong accepting an outside PR for a signing key. No offense.

Thoughts @akkadotnet/core @akkadotnet/contributors

[cptjazz]

None taken.
I'm not sure what your concern is. It should not make a difference where it was created, does it?
Or is it about having the key present in the repository here? The MS guidelines state:

CONSIDER adding the strong naming key to your source control system.
A publicly available key lets developers modify and recompile your library source code with the same key.

[Aaronontheweb]

I think @sean-gilliam is thinking of Authenticode signing, which works similarly to SSL - key has to be kept private to prevent impersonation.

[Aaronontheweb]

Strong naming doesn't work that way though, since it's not actually a security mechanism - just a fingerprinting mechanism for strongly identifying a specific name and version of an assembly

[sean-gilliam]

Ah gotcha. Yea I was mixing it up. Sorry guys.