cbufp: refactor and format
tests: use MAX_SZ parameter instead of hard-coded value
cbufp: break dependency with cbuf

Break the dependency of using a cbuf to return the garbage-collection list
from cbufp_collect() by mapping a shared page between the cbufp manager
and each client component. The list is stored in a ring buffer that is
accessed via a ck_ring structure located at the start of the shared
page.
cbufp: use continuous ring buffer in shared page
cbufp: add unit test interface for cbufps
cbufp: fixes from review
cbuf: make calling cbuf2buf on a cbuf by its owner an error
Merge pull request #93 from gedare/cbufp

Cbufp