Removed id generator mutex, replaced by a ssynchronization facility (which use a mutex but it's simpler to use).
Cleaning: removed all code from previous api (still accessible from history, see master) and fixed some backend include;
The resource system have not been touched yet.
This compiles but there is not implementation.
Fixed future not movable implicitly on return (bug from boost<1.54)
Fixed backend unit tests.
backend: began Sequence implementation, basic data;