improve logs

Egid doesn't need to expose the long value anymore
Added a lot more debug informations
Added a new SwapEntityGroup that declare explcitly (by contract) which group the entity must be before the swap

fixed use of PlatformProfiler
I decided to support empty EntityViewStruct

make EnginesRoot dispose itself

int cannot be used anymore to change a group, only ExclusiveGroups from now on

fix code for entity operation submission
clarify variable names

improve throwing of exceptions

improved tracking of entity groups (maybe fixed some bugs)

improve code
add more debug  checks