Added code templates with three initial templates

agent to create a boilerplate agent
outlet to create iOS outlets with attribute
uncheck to wrap an unchecked<type> declaration
virt to create an abstract definition with default virtual

They are many more so please contribute.
Merge pull request #649 from 7sharp9/codetemplates

Added code templates to addin with four initial templates
Add missing reference to test project after upgrading to XS 5.2.
After upgrading to XS 5.2 running the tests would fail with TypeInitializationException with a reference to a type from this dll.

Also, XS 5.2 made modifications to repositories.config, I thought it best just to include them.
Add default filenames to F# file templates
Merge pull request #652 from rojepp/default_filenames

Add default filenames to F# file templates
Merge pull request #651 from rojepp/xs52tests

Add missing reference to test project after upgrading to XS 5.2.