adding a constraint (maximum number of records) to pager_query

while pager_query generates a multi-page view of the database query result, it doesn't support a constraint that could limit the total number of rows.
the LIMIT clause of SQL is used by this function, so developer can not put a limit on number of rows / pages returned by pager_query.

for example, we have a database table that includes 1000 records (with a timestamp field that shows the last update time) and we would like to create a view that displays only 100 recently updated records in 4 pages (25 records per page)....

I created a patch that adds a new argument ( with default value of 0 ) to the pager_query which allows developers define the maximum number of records (in this example 100) in the query resultset.