use callParent to call parent's method.
add a mechanism to return data set by filter (bypassing parent's call).
create Hook directory, and HookObject stuff for future use.
tested HookObject code.
Query not to have Pdo as member property (cannot serialize).
test the Pagination.
split saveQuery into setQuery and saveQuery.
test Pagination using more realistic code.
clean up pagination code.
$pager->query{Total|Page} for getting result.
also use limit and order methods in query, thus removing page method.
add a sample queryPageWithNext for next-page type pagination.
removed argument $page from setPageToQuery method.
add comments.