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
mcserver: log if vbucket master is heuristically changed

Change-Id: Ic700abeccfe1ad0b68898c54bc7f524ea68caa36
Persist vbucket configuration heuristics across updates

Change-Id: I2b5d3390c8566fed705c2eaec5d421973bb68ec9