Fix @manage(include=[]) behavior.

[brunodonassolo]

Hi,

I started working with Calvin and creating some applications.

I create this pull request to fix a small problem in the manage statement. The manage doc says: @manage(include = []) # Manage nothing

So, I expect that no attribute will be automatically managed by Calvin. Is it right? However, the actual behavior is the same as @manage() that automatically includes all instance variables known.

I tried to fix it and added a small UT to cover this case. Please let me know if I misunderstood something or if you have some tip to improve the code.

Thanks.

[olaan]

Looks good to me. Thanks!