Fix - adapt to the new TEC settings

[Camwyn]

Fix settings so they save correctly, includes updating the settings to:

• fit into our new settings styles,
• save properly,
• utilize the TCMN settings object

I also:

• fixed an issue where the legend styles would not load on the FE,
• updated the plugin requirements to match TEC,
• deprecated some functions properly,
• used our views manager to get the list of active views (rather than hardcoding and using class_exists for ECP)
• removed out of date donate links and repo links

TECTRIA-417

[afragen]

Does the Reset button need a similar fix to test for empty?