Create subscription list during creation of newsletter category.

[tkuldeep]

• During creation of newsletter category, we will add users filters so that subscription list can be created.

[tkuldeep]

• I am creating filters using form, as using view expose form [Expose into block]. It is not possible to insert a block into a form. And If I directly try to insert form, it requires views context and other things. So I left that.
• I thought what is benefit, if we use view expose form, as we have to add filters programmaticaly.
• So I choose to alter form.
• According to user fields in account page, filters have been created. Currently filter is for
  • Taxonomy Term
  • Text field
  • List Select
  • Multiple checkboxes.
• Upon these filters, resulted users get subscribed to newsletter.
• If no filter is selected, then all the users will subscribed to that newsletter.

I am storing relation as tid, filters C1, F1:A;F3:B,C;F5:D,E,F. Reasons:

• Always there will be two columns, no change in the number of columns according to number of filters.
• There will be always a new row for a new newsletter category.

[tkuldeep]

@mukeshagarwal @sumeetpareek @basantsharma

• Please review this pull request.
• So that I can do work further.
• Some things I will update
  • My commenting style.
• Now creation of newsletter category will become heavy task, so we have to do in batch process.

[sumeetpareek]

@tkuldeep I see that @mukeshagarwal had some amazing code review on this. I would like to test this out on my local site, but perhaps after EC2 setup is done.

[mukeshagarwal]

@tkuldeep will close this after i test it on dev