node cache don't need to get all the information about every
candidate node. For huge clusters, sending full node information
of all nodes in the cluster on the wire every time a pod is scheduled
is expensive. If the scheduler is capable of caching node information
along with its capabilities, sending node name alone is sufficient.
These changes provide that optimization in a backward compatible way
- removed the inadvertent signature change of Prioritize() function
- added defensive checks as suggested
- added annotation specific test case
- updated the comments in the scheduler types
- got rid of apiVersion thats unused
- using *v1.NodeList as suggested
- backing out pod annotation update related changes made in the
1st commit
- Adjusted the comments in types.go and v1/types.go as suggested
in the code review
