Update documentation and small refactoring in dataset/query.rb
Update documentation and small refactoring in dataset/query.rb

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