move a couple of helper functions for writeParentPages into it.  like what was done with writeOveflow.  of course, both of these functions are themselves helper functions.  taking this process to its logical end, all this stuff will end up inside BTreeSegment.Create.
move a couple of helper functions for writeParentPages into it.  like what was done with writeOveflow.  of course, both of these functions are themselves helper functions.  taking this process to its logical end, all this stuff will end up inside BTreeSegment.Create.

ericsink/LSM,ericsink/LSM