Updated the manifest

Change the manifest file to include support for both 2012 and 2013.
Strong named references

Added a strong name to all of the DLLs which are versioned by Visual
Studio.  This prevents builds of Encourage from incorrectly binding to
later versions of the SDK.  Correct builds must bind to the 2012 version
of the SDK
Added the reference assemblies

These assemblies allow for builds on machines with 2013 only installed.
Minor fixups

Fixed a couple of issues

- The ReferencePath annotation must be absolute, not relative else
MsBuild will error on some configurations
- The reference to the shell needed to be 11.0 not 10.0
Merge pull request #10 from Haacked/fixes-build

Fixes 2012 + 2013 support