Reviewed and splitted the persistence guide

[mnapoli]

#22

• the MVC guides are no more
  • The "HTTP Request Handling" has moved to the "How Piwik Works" category
  • Controllers and Views have moved to the Web Interface category, along with pages and all
  • "Piwik APIs (Models)" has been moved to the HTTP Reporting API category and hase been renamed to "Piwik APIs" (it had nothing to do with a model layer)
• for the "Persistence & MySQL" guide:
  • Simplify "The MySQL Backend" guide #39 I have removed the SQL CREATE TABLE and merged the pertinent information (e.g. explanation of indexes or table naming strategies) into the "Entity" descriptions (where we list each property of each entity): it cleared up things a lot
  • I have extracted "How plugins can persist data" into a separate "Plugin Data" guide
  • I have renamed "Persistence & The MySQL Backend" to "Piwik Data"

Here is what the menu looks like now:

Hopefully now it's clear what these articles contain…

[mnapoli]

There's also the guide All About Analytics Data that duplicates a bit the Persistence one… But those 2 guides are huge, it was impossible to do something meaningful at once…

[mattab]

->Views

[mnapoli]

fixed

[mattab]

nice improvement! 👍