Set 'o patches

I've committed changes to do the following:

o Fix buffer overrun possibilities in date/time handling
o Handle fixed-length char and bit literals
o Implement IS OF type predicate
o Define macros to manipulate date/time typmod values
o Map hex string literals to bit string type (may change later)
o Map CREATE TABLE/OF to inheritance. May change later
o Implement WAL log file location support using "-X" and PGXLOG

                     - Thomas