makeids: ID list for mergeing PSID
Description
this list is taken from
http://ideas.repec.org/c/boc/bocode/s457040.htmlDetails
this function hardcodes the PSID variable names of
"interview number" from both family and individual file
for each wave, as well as "sequence number", "relation to
head" and numeric value x of that variable such that
"relation to head" == x means the individual is the head.
Varies over time.