Scope of types for named values in attributes improperly set as assembly where attribute is defined

fixes https://github.com/Microsoft/visualfsharp/issues/82
closes https://github.com/Microsoft/visualfsharp/pull/568

commit a7e74c8cba301d39bb5b1d07f448dc4bcef88967
Author: latkin <latkin@microsoft.com>
Date:   Thu Aug 13 16:55:32 2015 -0700

    Add tests

commit 6c6cb0e0ebae07c1e55847e2ddbab72bdcffef54
Merge: d2a25c8 01dc5083
Author: Don Syme <donsyme@fastmail.fm>
Date:   Tue Aug 4 20:05:22 2015 +0100

    update

commit d2a25c8db9c55d1ee0bd78c140355ccaa9130fee
Author: Don Syme <donsyme@fastmail.fm>
Date:   Mon May 11 12:44:15 2015 +0100

    updates to fix (3)

commit 1097c068a457585c1e303e788d6bbb792a71e32d
Author: Don Syme <donsyme@fastmail.fm>
Date:   Mon May 11 12:42:43 2015 +0100

    updates to fix (2)

commit 27c926891d1671edc6c174ee676eece370cbdc78
Author: Don Syme <donsyme@fastmail.fm>
Date:   Mon May 11 12:40:47 2015 +0100

    updates to fix

commit fb3a470b9ec90bc81f4c2289d0c0c7a6c7e3cebe
Author: Don Syme <donsyme@fastmail.fm>
Date:   Mon May 11 12:36:13 2015 +0100

    fix for 82