Allow actions to accept db protocol as parameter

[daisy-ycguo]

In the database-actions, https is hard coded in the source code. (see a sample here) So all database-actions cannot support databases which accept http connection only.

Adding a new parameter protocol to database-actions can resolve this issue.

[daisy-ycguo]

While, I also notice this package cannot manage those Cloudant db which doesn't support https connection. It has been hard coded in the action source files to use "https".
We should fix this too.

[jasonpet]

I do not follow your original comment about changesWebAction. I agree with you about the hardcoded files for the other actions. I use couchdb with http for the changes action and it works fine.

[daisy-ycguo]

@jasonpet, you are right. My original comment was wrong. changesWebAction works fine for couchdb with http. I will change the title and description to highlight the hardcoded files.

BTW, /whisk.system/cloudant/changes can accept parameter protocol, while other actions cannot. We should document this.

[jasonpet]

@daisy-ycguo - please feel free to submit a PR to update the documentation or a fix for this