queryobj: Add EverBound flag, making ISQuery() return false before BeginQuery()

queryobj: Add EverBound flag, making ISQuery() return false before BeginQuery()

This flag allows for the specified behavior that GenQueries reserves a name,
but does not associate an object with it until BeginQuery. We allocate the
object immediately with the new EverBound flag set to false, and then set the
flag to true at the time of BeginQuery.

This allows us to implement a conformant IsQuery function by checking the
state of the new EverBound flag.

This fixes the following es3conform tests:

	occlusion_query_genqueries
	occlusion_query_is_query_nonzero

and the following piglit test:

	occlusion_query_lifetime

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>