add support for logs

[zwetan]

not logs like the redshell option -Dastrace N
but logs in /varlogs/redtamarin/2016-01-15.log
which keep a timestamp of what have launched redtamarin

for ex:

2016-01-15 00h05m00 zwetan redshell_dd program.abc -- a b c
2016-01-15 00h06m00 root   redshell cronstuff.abc
etc.