Support for DB index management

v0.8.3 introduces support for custom user-definable indexes through a simple API in the system/db package.

func Index(namespace, key string) ([]byte, error) {}  // getter
func SetIndex(namespace, key string, value interface{}) error {} // setter
func DeleteIndex(namespace, key string) error {} // delete key in index
func DropIndex(namespace string) error {} // remove index and all key/values

To get the latest version:

$ go1.8rc3 get -u github.com/ponzu-cms/ponzu/...
$ cd $PROJ && ponzu upgrade

Better api.Externalable responses for apps/clients

#55 (feature) - types that implement api.Externalable now return responses if data was sent and saved successfully. This will help apps/clients to use data to build UI or confirm to users that requests were successful or redirect a user to their content.

Example response to a POST /api/content/external?type=Review which also implements api.Trustable

{
  "data": [
    {
        "id": "6", // will be omitted if status is pending
        "type": "Review",
        "status": "public"
    }
  ]
}

More control, minor bugfixes

Ponzu developers now have more control over the request/response lifecycle inside the content types through many of the interface methods provided in packages such as api and item.

#47 (feature)
#45 (bugfix)

Repeater input consistency & system backups

Happy to add some new features and minor fixes:

#39 - now the repeater inputs will have consistent order based on how they are displayed in the CMS
#42 - system.db, analytics.db and uploads can be backed up using http endpoint: /admin/backup and providing a query param source set to {system,analytics,uploads}. See the comment explaining usage: #42 (comment) (will be documented in the wiki)

To get it, run:

$ go1.8rc2 get -u github.com/ponzu-cms/ponzu/... # sub go1.8rc2 with your Go binary if you run 1.8
$ cd $GOPATH/src/your/project && ponzu upgrade

CLI updates

The plan for Ponzu as we move closer to Go 1.8 release is to make minor updates (like this release -- all small fixes to the CLI) and patches, bumping the release tag up to 0.9.0 along with Go 1.8 release.

Once we have the official release and more people have 1.8 installed, we'll work on locking down the APIs and finalizing the set of interfaces and how they work to tag a 1.0.0 by end of February 2017.

get it, build it, generate it, run it, add it and upgrade it

Finally ready to share this - based on my own production apps running for weeks, it's pretty much ready for use.

Need some feedback on internals, how to test things, what I'm missing and generally what is good/bad!