Add support for "datetime2" data type in MS SQL.

That's a blind fix, or almost blind: we're given some information but I'm
not in a position to test the fix myself. Hope it works.

Fixes #1036.
Fixes #1018.

src/monkey/mssql.lisp

@@ -95,7 +95,11 @@
              (:syb-int8 (mem-ref data :int8))
              (:syb-real (mem-ref data :float))
              (:syb-flt8 (mem-ref data :double))
-             ((:syb-datetime :syb-datetime4 :syb-msdate :syb-mstime)
+             ((:syb-datetime
+               :syb-datetime4
+               :syb-msdate
+               :syb-mstime
+               :syb-msdatetime2)
               (with-foreign-pointer (%buf +numeric-buf-sz+)
                 (let ((count
                        (%dbconvert %dbproc

src/sources/mssql/mssql-schema.lisp

@@ -170,6 +170,7 @@
   (case (intern (string-upcase type) "KEYWORD")
     (:time           (format nil "convert(varchar, [~a], 114)" name))
     (:datetime       (format nil "convert(varchar, [~a], 126)" name))
+    (:datetime2      (format nil "convert(varchar, [~a], 126)" name))
     (:smalldatetime  (format nil "convert(varchar, [~a], 126)" name))
     (:date           (format nil "convert(varchar, [~a], 126)" name))
     (:bigint         (format nil "cast([~a] as numeric)" name))