Update project files generated for visual studio

Add headerfiles to the project settings

Change-Id: Ia588c97d4c27f7bbc11c3ff93353b07a7607499c
Reviewed-on: http://review.couchbase.org/33997
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>