give consistent results for all datatypes. Types float4, float8, and
numeric were broken for NaN values; abstime, timestamp, and interval
were broken for INVALID values; timetz was just plain broken (some
possible pairs of values were neither < nor = nor >). Also clean up
text, bpchar, varchar, and bit/varbit to eliminate duplicate code and
thereby reduce the probability of similar inconsistencies arising in
the future.
regression tests for specific types, and move a few others to the
cross-type "horology" test.
Rearrange the test order slightly, and move the abstime test to the
"parallel safe" area.
Hand-patch the results for "1947" and for "solaris", so those may not
be exactly correct.