Had to fix the ApplicationTree and Application classes to lazily call the Cache method
(which is no renamed to EnsureCache) so that we could set the config location in the unit tests.
This should also improve performance a teeny bit and allow for better error handling if required.
Updated InternalsVisibleTo declarations.
Updated the ApplicationTest test to use a new base class as a test to install a local sqlce database
for testing against.
Added Umbraco.Core project.
Added Umbraco.Web project.
Created new sln folder Legacy
