Kontainer plugin for Umbraco 8

Adds a media picker to pick media items from a Kontainer repository.

Current features:

• Support for multiple Kontainer instances.
• Select single or multiple items
• Sort items if multi selection is enabled
• Minimum and maximum selection limits. Eg. Select at least one but no more than 5.

The picker stores the following information:

• Url: The absolute URL to the selected item
• Type: The type of item that has been selected, eg. "image"
• Extension: File extension, eg. "docx"
• Description: Short text that describes the item. This is edited in the Kontainer UI
• Alt: Alternate text, also edited in the Kontainer UI. Used to describe images for screen readers.

To use the new media picker, you must first add a new data type in the settings section and choose the "Kontainer Media Picker" property editor.

Current limitations:

• Changes in Kontainer is not reflected in the selected items
• It is not possible to only select specific types