Freemarker MVC module updates.

- FreemarkerViewProcessor made package-private and moved to root module package.
- Added support for exposing non-map models under default "model" name.
- Added test to test the new default "model" name support.

Change-Id: I7f64504f3d02fb047217d66d9ee2980f56004442
Signed-off-by: Marek Potociar <marek.potociar@oracle.com>