Merge branch 'improve-projects-collecting' into 'master'

Improve projects collecting

Refactor code that cause unexpected AR behaviour.

For example this works fine:

    @projects = Project.personal(@user).accessible_to(current_user)
    @groups = @user.groups.accessible_to(current_user) # OK

But

    @projects = Project.all
    @groups = @user.groups.accessible_to(current_user) # PG:Error