Description:
------------
When sending batch requests to the mssql server, the mssql result is having 
dbcancel() called prematurely on the handle (via the _free_mssql_result function).

Because we are processing batches of the result set we need the query to stay open 
until we are finished fetching all the rows (not just the first batch).

In a non-batch scenario, it is fine to cancel the query after the first batch is 
called, because all rows have been fetched.

I have attached a patch, which "fixes" the problem, but probably not in the right 
way. I have no clue what the right way actually would be or what the repercussions 
of applying the patch are. It is meant for illustrative purposes only.

Test script:
---------------
<?php
// Connect to MSSQL and select the database
$link = mssql_connect('hostpath', 'user', 'pass');
mssql_select_db('db', $link);

// Send a query to a table that has 12 rows
print "Given a table with 12 rows:\n";
$result = mssql_query('SELECT * FROM tablename', $link, 5);

do {
    while ($row = mssql_fetch_assoc($result)) {
        print "Row found\n";
    }

    $remain = mssql_fetch_batch($res);
    print "Remainder $remain\n";
} while ($remain > 0);


Expected result:
----------------
Given a table with 12 rows:
Row found
Row found
Row found
Row found
Row found
Remainder 5
Row found
Row found
Row found
Row found
Row found
Remainder 2
Row found
Row found
Remainder 0


Actual result:
--------------
Given a table with 12 rows:
Row found
Row found
Row found
Row found
Row found
Remainder 1
Row found
Remainder 0