Added `JDBCUtils#executeQueryMapList()` for convinience. Close #2

It makes `List<Map<String,Object>>` from ResultSet and return it.
This method is really useful to write an admin site using freemarker :)
Merge pull request #3 from tokuhirom/features/executeQueryAsMapList

Added `JDBCUtils#executeQueryMapList()` for convinience. Close #2