Make it possible for Plan.members to include/exclude Steps of users into main plan.

[mindey]

1. Members of project may [Include/Exclude] step from member by a click of button on step (ajax)
2. By default, steps of non-members are excluded from main plan, and only visible visiting via ?user=username
3. By default, steps of members are included in the main plan.

This way, members can look at various users' suggested step lists, and cherry-pick what they want to include into their main plan. Moreover this way, every user can have their own proposals, just look at my proposed plan at ?user=username.

[mindey]

However, this way, we have a little bit of a problem with Step ordering, right? A Step might have one Step.priority for user's personal plan offer, and another Step.priority for the main Plan, so, we would have to and prevent default ordering, order steps by user's order, if ?user=True,

So, we need two attributes:

Step.included = True/False
Step.user_priority = IntegerField

@aliev