Initial stab at providing templates

Not exactly satisfied, but it's working, so stash it for safe keeping.
Will iterate.
Updated .gitignore

Remove sln cache file when building with msbuild
Different method of supplying templates

Doesn't use the file injected layers, but injects a layer directly on plugin load. Solves a couple of problems with the file based approach (better cleanup when plugin is removed, doesn't get loaded when plugin is disabled)