Expand the advanced_associations.rdoc file
Expand the advanced_associations.rdoc file

All examples have now been tested, and an integration test suite will
be committed soon starting with some of these examples.

pfarrell/sequel,reubano/sequel,dennis-d/custom_sequel,mpalmer/sequel,pfarrell/sequel,Marketcircle/sequel,davidbegin/sequel,knut2/sequel,offshore-safety/sequel,seeARMS/sequel,gferguson-gd/sequel,gferguson-gd/sequel,nju520/sequel,bigfix/sequel,seeARMS/sequel,beni55/sequel,t-morgan/sequel,yazshel/sequel,chef/sequel,mpalmer/sequel,nju520/sequel,uhoh-itsmaciek/sequel,knut2/sequel,yazshel/sequel,beni55/sequel,offshore-safety/sequel,offshore-safety/sequel,dennis-d/custom_sequel,davidbegin/sequel,reubano/sequel,freshpay/sequel,nicohvi/sequel,nicohvi/sequel,freshpay/sequel,t-morgan/sequel,uhoh-itsmaciek/sequel,petergunz/sequel,tmm1/sequel