Permission error on log-file creation

[kuraga]

PermissionError: [Errno 13] Permission denied: '/tmp/ebuildtester-app-editors-nano.log'

Propose to have individual log files...

1. This avoids permission errors.
2. This avoids the (previous) log erasing issue.

The one question (two) are the path and the log-file name...

[stkw0]

The first point is probably due to the same than the other issue (umask 0027).