Add "Set as Default Top" and "Generate as Top" feature

1. Allow users to set the default Top capsule. Default top capsule is
stored in model eannotation.
2. Provide users ability to generate any capsule as a top capsule from
the context menu.

Change-Id: Ife8c2c6dbe8d115758cedc67d811e1e95daec13a
Signed-off-by: yroh <ysroh@zeligsoft.com>
11 files changed