Request for review (s) - NPG: Replace the ChunkList implementation with class FreeList<Metachunk>

[Jon Masamitsu]

For the perm gen removal project the ChunkList class
which implemented a simple freelist of Metachunk's was added.
This change replaces ChunkList with FreeList<Metachunk>.

Changes include

- Deletion of ChunkList
- Code to initialize the freelists in the FreeList style
- Replacement of call to ChunkList methods with the
equivalent calls to FreeList methods.

http://cr.openjdk.java.net/~jmasa/8011173

Thanks.

Jon