#128 support for no terminator in bcp format file

[Anonymous]

bcp_colfmt requires a null pointer when specifying no terminator, and currently barfs when zero length is supplied with non-null pointer (as is the case when specifying an empty string for terminator in the format file).

The attached patch fixes the parsing of the bcp format file to pass a null pointer when an empty string was specified as terminator.

NB: a nice side effect of this is the possibility to use a named pipe as input to freebcp

When specifying a prefix length and no terminator for all columns in the format file, freebcp will not perform any fseek on the input stream, allowing the use of named pipes.

[Nobody/Anonymous]

[Frediano Ziglio]

Applied, at the end!