codeintel: move LazyClassAttribute into common module
* as I don't want to write the same import handling everywhere

(integrated from komodo (trunk) change 81376 by toddw)

git-svn-id: http://svn.openkomodo.com/repos/openkomodo/trunk@13447 b87d16e7-d29f-4ee1-b5ec-817d645d335f