Acme: button 2 execute does not set $TERM

[Connor Taffe]

Hi folks,

As an Acme user, programs which print colors are difficult to work with. Well-behaved programs would realize their output is not a tty; programs using tput will automatically disable color in win because TERM=dumb; other programs may respect NO_COLOR or require program-specific configuration.

I noticed today that executing `tput setaf 4` via button two printed an escape sequence whereas running it in win did not. Executing `echo $TERM` with button two revealed that TERM=xterm-256color; likely inherited from the shell I opened acme in.

The obvious solution is to set TERM=dumb in the wrapper script I use, however I think it would be wise for Acme to set TERM=dumb when executing with button two, knowing that the output will (by default) end up in +Errors.

Thanks,
Connor Taffe