Introduce new constant DATETIME2BIND

Used for supporting binding to local variables of type TDS_DATETIMEALL.
This allow to better support new MS date/time on dblib.
Do not declare pver as static

This make the function thread unsafe, avoid it.

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Constify dashes

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Optimize tdsvername_t structure

As all names are quite short use a static buffer instead of a pointer.

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Fix integer overflow for new MS time types

During conversion from string to new MS date/time types time loose
precision causing corruption of time.

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>