TF: remove BT.1361, rename bt709 to bt1886, and take default luminances from BT.2035
This series has three independent changes:
- Removal of the historical TF BT.1361 which was withdrawn in 2015.
- Renaming bt709 to bt1886, because BT.1886 is what we actually use.
- Changing bt1886 to have the default luminances according to BT.2035 which all of BT.601, BT.709 and BT.2020 refer to.
More details in each commit message.