Fix off-by ones in UTF-8 parsing in terminal
Fix off-by ones in UTF-8 parsing in terminal

- 11100000 (224) was misinterpreted as 2-byte sequence, whereas it defines a 3-byte
- 11110000 (240) was misinterpreted as 3-byte sequence, whereas it defines a 4-byte

Makes it possible to type characters from the Supplementary Multilingual Plane such as 𐎒 and 𝄐.

ohAitch/urbit,ohAitch/urbit,urbit/urbit,juped/your-urbit,jfranklin9000/urbit,jfranklin9000/urbit,urbit/urbit,juped/urbit,juped/your-urbit,juped/urbit,cgyarvin/urbit-1,ohAitch/urbit,urbit/urbit,max19/urbit,juped/urbit,cgyarvin/urbit-1,ngzax/urbit,ngzax/urbit,max19/urbit,jfranklin9000/urbit,max19/urbit,juped/your-urbit,ohAitch/urbit,ohAitch/urbit,max19/urbit,urbit/urbit,cgyarvin/urbit-1,ngzax/urbit,max19/urbit,juped/your-urbit,urbit/urbit,juped/your-urbit,cgyarvin/urbit-1,ngzax/urbit,juped/your-urbit,cgyarvin/urbit-1,ohAitch/urbit,juped/urbit,ohAitch/urbit,jfranklin9000/urbit,jfranklin9000/urbit,juped/urbit,juped/your-urbit,juped/your-urbit,cgyarvin/urbit-1,cgyarvin/urbit-1,juped/your-urbit,juped/urbit,max19/urbit,ngzax/urbit,ohAitch/urbit,jfranklin9000/urbit,ngzax/urbit,ohAitch/urbit,cgyarvin/urbit-1,ohAitch/urbit,juped/your-urbit,jfranklin9000/urbit,juped/urbit,ngzax/urbit,urbit/urbit,max19/urbit,juped/urbit,max19/urbit,urbit/urbit