Created a new namespace called Dali.Constants and wrapped the
AlphaFunction.BuiltinFunction enum. Added a new constructor to cope
with this change.
hello-world.cs is also modified accordingly.
Change-Id: I86f9b079920c65f531d4175366af8578b61ccb5c Signed-off-by: Ravi Nanjundappa <nravi.n@samsung.com>