micropython/micropython — pull request #491 by aitjcize (2014-04-15 03:39:14+00:00)
Title: Remove uneeded output in REPL.

REPL shouldn't print the ret value if ret != None

for example, the output should be
```
>>> import sys; sys.stdout.write('test')
test>>>
```

instead of
```
Micro Python build bbae42d on 2014-04-14; UNIX version
>>> import sys; sys.stdout.write('test')
test4
```