Currently when we open a new summary panel

- we display the rrd with default hour timeframe
- then we refresh it
- then we update from timeframe selector

With this patch:
- We display the rrd with timeframe from selector, or if not defined default hour
- We update from timeframe selector value if timeframe && cf are differents from current value
Signed-off-by: Alexandre Derumier <aderumier@odiso.com>