feature: add step-profit

[t0mZ4]

Hi,

will be very nice to set step-profit so if it reaches the desired profit %, it monitors and if % goes higher, it will ride it and only sell once it drops to or slightly below the set profit.

so if i set 1.5% profit, it will not sell at 1.5% if price increases, only if it drops to 1.4-1.3 it will sell. or have a setting to determine step.

[yasinkuyu]

Great idea. It'll be helpful.