#146 add Grouped shapes but has its own Timeline

[Mj Mendoza IV]

Asset is Grouped shapes but has its own Timeline and can be instantiated multiple times as user desires.

Sample use: Birds in the background where user will only animate one bird Asset then populate the scebe with several copies of the bird Asset.

[Mj Mendoza IV]

partial implementation on https://sourceforge.net/p/kage/code/798/