create build -> add users dialog is misleading

[karenetheridge]

When creating a build, after entering the preliminary fields, the "Add Users to Build" dialog is presented. The operator might add a lot of users to this build as read-only or read/write, only to discover that the next dialog after this is "Add Organizations to Build", which is a lot simpler when many users are already grouped into organizations.

Could these two dialogs be combined into one, for configuring access all at once?