contrib: bitcoin-tool
network: 0.1% coinbase output donation.

 - starting on july 8th 2014 (date may change), 0.1% coinbase total
   output goes toward development and hosting costs.
 - to be valid, coinbase transaction will have to :
   - have its first output going toward devel address, with 0.1% of
     total coinbase output.
 - such coinbase transaction will be required for blocks to be accepted
   by the network.

 - a network alert will be sent as soon as a public release is ready, so
   everyone can upgrade in time.

 - NOTE: pool operators will have to include this mechanism in their mining
   pools.