The Link Speed of a port reads as "Auto" if unspecified.

Signed-off-by: Min Chen <minchnew@gmail.com>
The Configuration Tab is now responsive. This patch also includes some minor
fixes:
1. Use table to present data if possible;
2. The looking of panel headers is now consistent (in panel-default theme);
3. If some features are not configured, a light yellow alert is shown;
4. Flow rules whose match fields and actions are very long are now presented
visually friendly.

Signed-off-by: Min Chen <minchnew@gmail.com>