Fix up internal.h

This rearranges some indentation and migrates some "cached"
configuration variables to the actual vbucket configuration via widely
used macros.

Change-Id: I02414913ecb68d445b73198f98144929ac1f8a92
Reviewed-on: http://review.couchbase.org/42401
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>