Now it works muliple selection and select other object when we already have selected the other...
New interface added for the BillboardManager to construct the (generic) atlas, not tested yet, compiling OK.
BillboardManager v1 (compiling version) is ready, need to test with the real texture atlas.
The BillboardManagerBuilder (BMBuilder) already done (not tested).
Modified all the other classes that were using the BillboardManager