Order commissions by DateEarned (or other field as passed into the query method).

This fixes an error in the commissions sync where it was stopping the sync loop due to earlier commissions appearing too soon in the array.
Merge branch 'master' of ssh://novaksolutions.repositoryhosting.com/novaksolutions/infusionsoft-php-sdk
Add fieldExists to Lead generated class
Merge branch 'master' of github.com:joeynovak/infusionsoft-php-sdk