In short, this is unicode in Python 2 and str in Python 3.

[WebUI] Fix auto unit helper

...otherwise the file handle is left open due to the use of return
before the handle closure.

OK FreeBSD, OS X and Windows.

OK FreeBSD, OS X and Windows.

OK FreeBSD, OS X and Windows.

This reverts commit 79dc79f9.

See PR #683.

Changed percentage bars to use an explicit assertion error if valid is outside of the expected range.

Correct an issue while exiting Docker sub process on Python 3.4. Correct it for both Python 2 and 3 thnaks to http://stackoverflow.com/questions/27102881/python-threading-self-stop-event-object-is-not-callable

tback: docker.containers() can return None

```
Traceback (most recent call last):
  File "/usr/bin/glances", line 9, in <module>
    load_entry_point('Glances==2.3', 'console_scripts', 'glances')()
  File "/usr/lib/python2.7/site-packages/glances/__init__.py", line 119, in main
    args=core.get_args())
  File "/usr/lib/python2.7/site-packages/glances/core/glances_standalone.py", line 62, in __init__
    self.stats.update()
  File "/usr/lib/python2.7/site-packages/glances/core/glances_stats.py", line 156, in update
    self._plugins[p].update()
  File "/usr/lib/python2.7/site-packages/glances/plugins/glances_plugin.py", line 633, in wrapper
    ret = fct(*args, **kw)
  File "/usr/lib/python2.7/site-packages/glances/plugins/glances_docker.py", line 154, in update
    for c in self.stats['containers']:
TypeError: 'NoneType' object is not iterable
```

[Web UI] Truncate long message in monitor plugin

[WebUI] Hide RAID plugin if no data

Fix percpu when stats are missing

[WIP][WebUI] RAID Plugin