fixed con.lastInsertId();

gets the last insert id without using handleTag() cause it fails badly
lastInsertId() is needed for Manager (makeCache)
SELECT LASTVAL(); errors when inserting into a table that doesn't have a sequence (setval isn't called), handled by try/catch block
added testMultipleInserts() to make sure sequential inserts still work and lastInsertId() is accurate
added testSingleInsert() to make sure that normal inserts to tables that don't have sequences, don't break when calling lastInsertId();
all tests pass