[p750mmx]

v3.21.0 released

- Added: Support Edit Recording name, last played and play count
- Fixed: Use v3.6.1 of nlohmann/json to relax cmake version dependency for OSMC, fixes #194
- Added: Nightly channel reload check as default
- Added: Split out and move openwebif version checking to settings

It shows an update to 3.20 at this moment (I wasn't quite up to date), and while installing that version, Kodi crashes. I wait till 3.21 is refreshed on the update server