* clear trafficgraph on clear button click
* set default sample height
set default sample height so after clearing traffic graph have some
scale
* reduce available traffic graph ranges, add optimized graph data storage
reduce available traffic graph ranges to 10
(5m,10m,15m,30m,1h,2h,3h,6h,12h,24h),
store graph data so range change is possible,
data storage contains only necessary data to create graphs for all
supported ranges
eg. for 10m range storage only half of 10m samples - the second half is
calculated from 5m range samples,
encapsulate all traffic graph related data into one class
* code formatting corrections
QT_NO_KEYWORDS prevents Qt from defining the `foreach`, `signals`,
`slots` and `emit` macros.
Avoid overlap between Qt macros and boost - for example #undef hackiness
in #6421.
