Extend _oikp_download to support satellite sites

[bobbingwide]

Background

Bobbingwidewebdesign.com is undergoing a makeover, with existing content that was created as pages being converted to posts and new content being created for the referenced plugins and themes. The [bw_plug] shortcode has been changed to detect the locally defined plugin. We now need a method to link to the original source of the plugin. A QAD proposal is to extend _oikp_download to cater for plugins which don't have any related plugin versions. The theory being that these are satellite definitions.

Requirements

• create download links for plugins that are hosted elsewhere
• use optional fields for those situations where the link cannot be determined automatically.
• provide a read more link and live demo link as appropriate

Proposed solution

• change _oikp_download()
• provide links which open the page rather than perform a download - we don't know what version is required
• No longer display "Purchasable product: FREE" - add '#theme_null' => false to field registration
• Add _oikp_uri field to override automatic setting based on plugin_type - #theme => false

[bobbingwide]

When the referenced plugin is an oik plugin then the download link doesn’t work if oik-shortcodes is activated. This is because oik-shortcodes overrides a constant that’s used in oik_get_plugins_server(). The workaround is to set the plugin type to premium and supply the url in the plugin URI field. This will then cause the download button to link to the plugin’s home page. The other advantage of this is that the Changelog tab is not displayed

The fix either involves changing oik-shortcodes and libs/oik-sc-help to not set the shortcode parameters server until we know we have to or use a different routine to determine the server without overriding the constant BW_OIK_PLUGIN_SERVER