More precise network speed detection

On 1 GBit network it is possible to receive speed <1ms for 64000b of PING size.
This speed were not parsed so no speed was shown.
Also time value was set as INTEGER where 5/3 returns 1 instead of 1.6666666 so counted speed should be more precise.
Merge pull request #58 from ExSport/patch-1

More precise network speed detection