Update taxonomic backbone to World Flora Online

[AndrewIOM]

The Plant List 1.1 has been superseded by the WFO. Tasks:

• Update backbone taxa to WFO latest release. Use the latest static release from http://www.worldfloraonline.org/downloadData
• Ensure all read models are updated correctly and automatically to reflect name changes since TPL1.1.
• Change links to the plant list to point to WFO taxon pages (e.g. from GPP taxon pages).

"The Plant List (TPL) was a working list of all known plant species produced by the botanical community in response to Target 1 of the 2002-2010 Global Strategy for Plant Conservation (GSPC). TPL has been static since 2013, but was used as the starting point for the Taxonomic Backbone of the World Flora Online (WFO), and updated information can be found at www.worldfloraonline.org.

WFO is being developed by a consortium of leading botanical institutions worldwide in response to the 2011-2020 GSPC’s updated Target 1: to achieve an online Flora of all known plants by 2020. WFO welcomes feedback from users for improvements to its Taxonomic Backbone which is curated by a growing community of WFO Taxonomic Expert Networks (TENs)."