Bug in TypeInfoCache causes getObject to fail

Hello,

i have found a race condition in org.postgresql.jdbc2.TypeInfoCache. A
Map is created as a static member, but reinitialized for every new
instance of TypeInfoCache. That causes a race condition in
ResultSet.getObject(...), which then returns PGobject instead of the
correct type. Probably causes other problems as well. I have attached a
test case. The test case works best on smp machines (tested on a 4 way),
where it fails almost every time.

Also the maps in TypeInfoCache are created as synchronizedMaps, which is
unneccessary, slow and a potential source for further side effects. I
have removed that as well, and attached a fixed version of TypeInfoCache
from build 404. I leave the application of the fixes to the current and
other versions as an exercise to the committer ;-)

Have a nice day...

Till