[2.3.x] + additiona commit for implement task #1620
https://java.net/jira/browse/GRIZZLY-1620

"Make FilterChainContext attributes to be really copied (instead of using additional customAttributes)"
[2.3.x] + optimize first value set
[2.3.x] + don't create FilterStateElement every time we store a remainder
[2.3.x] + additional commit for: don't create FilterStateElement every time we store a remainder
[2.3.x] + implement improvement #1621
https://java.net/jira/browse/GRIZZLY-1621

"Optimize HeapMemoryManager to support pooling from 2 sides of the pool (instead of 1)"