Resource management by project or subproject

[ZoTyA1975]

Can I set the price in Resource management by project or subproject? It would be nice if I can do that because the price is not same in every project.

[vincentsels]

I can acknowledge that this would be a nice feature. A bit related to issue #13. Might add this if I find the time. Feel free to fork and implement it yourself through a PR ;)