Fix/connector sorting chaos

[edison23]

This PR proposes systematic connector sorting (employs display-order property as before) based on statuses. I devised it so that the connectors are sorted primarily by their functionality status and secondarily by their development status:

• functionality-status:
  • stable: 200
  • limited: 300
  • unknown: 400
  • experimental: 500
• development status:
  • active: X00
  • community: X20
  • dormant: X40
  • abandoned: X60
  • unknown: X80

Example results:

• actively developed stable connectors are 200, dormant experimental ones are 540, limited abandoned are 360, etc.
• stable and actively developed connectors are at the top with display order 200
• abondoned but stable connectors are lower (260) but still higher than those under that are active development but with limited functionality (300) or those that are dormant and of unknown functionality (440), etc.
• experimental connectors are at the very bottom, whatever their development status is (5X0)

This change is to be reviewed by the team before merge. If so desired, we can devise a different algorithm (e.g., prioritize development and support status?), it is easy to automatically resort the connector pages.

I realize that to a user viewing the list in the Docs, the sorting method would not be obvious, but it still prioritizes those actively developed usable connectors and I don't think the manual "organic" sorting we have there now gives the system away any better than this. This new system is at least, in my opinion, easier to explain to anyone contributing to the section.

Why not restructure the section to clearly divided subcategories (directories)? While nicely usable, I think it would be impractical because any time a connector would move from one category to another, it would mean changing its URL and setting up a redirect. The system I propose in this PR is easy to enforce automatically (by sed and grep), as well as easy to redesign (as in change primary and secondary sorting parameters).