These internal functions were no longer used or defined but
the prototype and stub were still present.

If this routine fails then return the error to the caller,
which will also prevent the task from starting.

Remove repetitive clearing of the global ID and unlocking
global table and replace with common implementation in the
idmap code.  In addition to removing repeated logic, this
makes deletion more like an inverse of creation, and provides
a common/single point where additiona deletion-related
logic can be added.

Fix #557, remove OS_ObjectIdMap/Unmap prototype and stub

Fix #565, propagate return code from OS_TaskRegister_Impl()

Refactored +dev in OS_VERSION macros