[FEATURE] Accurate gold to gem conversion tracking with alarm!!!

[gartkb]

Please make this happen, literally nobody has this feature. There's one site that I'm aware that has an attempt at this, but it's not very accurate, and it doesn't work unless you have the page open. The other is a java app for the desktop, that isn't very accurate and hasn't been updated in a long time anyways. GW2Efficiency seems to have done a fairly good job at calculating the exch rate fairly closely, but they have no ability to alarm. Thanks, love your app :)