JNC

• clean up and document better set/show commands
  • autoeval,
  • autolist
  • confirm,
  • different
  • linetrace
  • trace-command
  • listsize,
  • width
• more RsT formatting in set/show commands
• Silence "stty echo" failures in terminal detection
• Add set/show confirm
• Add ! suffix to kill command
• set $0 properly inside "eval" and "shell commands
• bump min zshdb version at least 5.4.1 to avoid memory corruption when setting $0
• other small fixes and doc improvements