Converting tutorial package names

[Andrus Adamchik]

Question to Michael G. - I noticed that 3.0 and 2.0 tutorials still  
import objectstyle packages. Do you have time in the next few days to  
replace that to 'apache'? If not I can do it myself, no biggie.

https://svn.apache.org/repos/asf/incubator/cayenne/main/trunk/pre- 
maven/tutorials/
https://svn.apache.org/repos/asf/incubator/cayenne/main/branches/ 
STABLE-2.0/cayenne/tutorials/

Thanks
Andrus