Queries return an interval that extends below a recent change

Examples: a9Uzc (cache always misses), btQdq (misses+long blobs),
eJ8YK, gsdQW

zgrep -B1 "Attempting to extend" server.gz

The easy way to trigger this is to add return NULL; to the top of
Store_Lookup

aJRTE 18645   HandlePut       (server.c:66):      Putting data <5799 065c5147> with key |....searchitemsbycategory.......> at [-inf,92)
aJRTE 18645 ! Store_Put       (store.c:196):      Attempting to extend interval of existing entry from [-inf,60) to [-inf,92) but data disagrees

a9Uzc always manifested this with searchitemsbycategory, though with
three different keys and different failing bounds for each key.  Some
of them had a lower bound of -inf, some didn't.  btQdq, eJ8YK, gsdQW
are similar, including the function.

Observed sequences: 
 eJ8YK (postgres, initDB, extend bug, +1 bug)

Status: resolved

SearchItemsByCategory and SearchItemsByRegion were using LIMIT without
ORDER BY, resulting in non-deterministic queries