Improve consistency on fork 1 and 5 recovery

[4miners]

When we need to deal with forks - two competiting blocks with same timestamp can happen, like here:

NODE-A:
[inf] 2016-12-16 05:46:01 | Fork - {"delegate":"7ac9d4b708fb19eaa200eb883be56601ddceed96290a3a033114750b7fda9d0b","block":{"id":"7178860889734481430","timestamp":17757960,"height":1573042,"previousBlock":"12148071383986657341"},"cause":5}
[WRN] 2016-12-16 05:46:01 | Delegate forging on multiple nodes - 7ac9d4b708fb19eaa200eb883be56601ddceed96290a3a033114750b7fda9d0b
[inf] 2016-12-16 05:46:01 | Last block stands

NODE-B:
[inf] 2016-12-16 05:46:01 | Fork - {"delegate":"7ac9d4b708fb19eaa200eb883be56601ddceed96290a3a033114750b7fda9d0b","block":{"id":"13396432513620010395","timestamp":17757960,"height":1573042,"previousBlock":"12148071383986657341"},"cause":5}
[WRN] 2016-12-16 05:46:01 | Delegate forging on multiple nodes - 7ac9d4b708fb19eaa200eb883be56601ddceed96290a3a033114750b7fda9d0b
[inf] 2016-12-16 05:46:01 | Last block stands

That can lead to network split - because block that was received first is winning one in such case, and not the older one as expected (both have same age). We need to ensure consistency here between all nodes on network, so I suggest implement following:

• when both blocks have same age - keep one with higher or lower (not matter) id (unique value)