Due to the special case of when the digits string was longer than 1 but
only contained the negative sign and a 0, it was incorrectly stripping
the 0 and attempting to parse "-" as a number.
The solution is to check an extra position along to make sure a trailing
0 is not immediately preceeded by a negetive sign.
Fixes#543
They now take ownership of the src argument.
Needed to change Scan to make a copy of []byte arguments as lib/pq apparently
gives Scan a shared memory buffer.
This adds PostgreSQL numeric mapping to and from
github.com/shopspring/decimal.
Makes pgtype.NullAssignTo public as external types need this functionality.
Begin extraction of pgtype testing functionality so it can easily be used by
external types.
David Hudson