Add a little test that shepherd doesn't try to compile nodes that aren't built

Hello @x-ma, 

Please review the following commits I made in branch 'nick-compilers'.

f5d9e061f061477b9491f5e43eeed9b679802643 (2013-10-22 13:17:14 -0400)
Add a little test that shepherd doesn't try to compile nodes that aren't built

Check list:


R=@x-ma