Deal with incomplete terminfo data

[loganzartman]

Ideally, we communicate with Unix terminals entirely using terminfo strings. However, many people/terminals have chosen unfavorable TERM environment variable values which point to terminfo entries that do not express the full capabilities of the terminal. Here are some ideas:

• provide our own terminal detection system
  • we may not need to vend a terminfo database, but just choose a better TERM value
• use xterm terminfo strings for any missing terminfo capabilities
  • most terminals are xterm compatible. If a certain capability is missing, we could just use one for xterm and hope it works
• not use advanced capabilities