Fixed 2004 core merge

General HRS cleaning file needed to drop some observations in the
imputed files per the codebook instructions, should fix problem with
some interviews having missing pn in the sic project
Added zip code to core ivws, hospital days fixes

Checked missing restricted data, missing pn
Added zip code to each core year, cleaning using previous or next wave
where missing
Truncated admission and discharge days for hospital stays to get
accurate days in the year in the hospital in cases where the hospital
stay overran the time window of interest
Spouse added table

Removed matched table creation in the +3 day hospice use definition
since we aren't using it
Added a table of overall sample statistics for KO's writeup