Increase spending limits

I think the current spending limits are too low, they are triggering board votes which take time and slow us down.

These are the new limits that I propose:

1. 1 Board member may spend up to $500 without consulting anybody
2. 2 Board members may agree to spend up to $1000, as long as there are no objections raised
3. 3 Board members may agree to spend up to $2500, as long as there are no objections raised
4. 4 Board members may agree to spend up to $5000, as long as there are no objections raised
5. 5 Board members may agree to spend up to $10000, as long as there are no objections raised
6. 6 Board members may agree to spend up to $25000, as long as there are no objections raised
7. The board must vote unanimously to spend more than $25000