Tracker: change summary

[GoldenGnu]

Add a summary of changes for each tracker point.

Examples:

• Count and value of Assets/market orders/ contracts
  • Added
  • Removed
  • Moved?
  • Price increased
  • Price decreased

Everyone is welcome to comment with suggestions!

[ericjeker]

• average the amount per day to smooth the curve (should be a toggle because it will prevent editing values)
• display the movement (% and value) from the first value of the graph to the last value
• display the information on mouse over for all the tracker points of one sync and not only one dot
• display a mark on a tracking point with edited values so we can quickly distinguish it in the graph