Display initial TPF as first frame's current duration.

[muziqaz]

When new WU is downloaded and started, there is some random TPF value shown until we complete 1%. It would be cool (and less confusing for new users), that TPF value column would count the time from the moment WU prints out 0% (starts folding). It would count the second (and minutes) till 1st frame is finished at which point it would switch to actual value of the TPF.