Handle cases where `message_args` is a list.

This can be reproduced by redefining a variable in a list comprehension. This
produces the error message `list comprehension redefines %r from line %r` with
message args `[xx, 120]` (a list).
Merge pull request #1 from lakshmivyas/bug/message-formatting

Handle cases where `message_args` is a list.
Update README.markdown
Update README.markdown
- should work now in unsaved buffers (creates temp file)
- fix for Python2 tempfile
Merge branch 'master' of https://github.com/JulianEberius/SublimePython