.venv @ 78a1340b652d

Intercept common IO errors exceptions.

When the task directory doesn't exist or when a file can't be read or written,
t.py fails with a full stacktrace exception. This change allows t.py to fail
more gracefully, printing the exception message, the relevant file, and then
exiting with an errorlevel code of 1.

# Non existant directory issue
/home/dereckson/dev/t ] ./t.py -t /nonexistent Lorem ipsum dolor
No such file or directory - /nonexistent/tasks

# File permission issue
/home/dereckson/dev/t ] mkdir test
/home/dereckson/dev/t ] ./t.py -t test Lorem ipsum dolor
/home/dereckson/dev/t ] chmod 000 test/.tasks.done
/home/dereckson/dev/t ] ./t.py -t test Lorem ipsum dolor
Permission denied - test/.tasks.done

t