Replace cost/benefit by iterations in report

wiki/src/blueprint/SponsorW/2017_12.mdwn

@@ -61,18 +61,17 @@ preliminary research work that we did, both in terms of user needs
 (through the survey) and technical feasibility (through the
 backend code written until now).
 
-The details is in our [[blueprint|blueprint/veracrypt#scope]] and here is a
-visual summary:
+We structure the scope of our work in four iterations. We will implement
+and upstream each iteration one after the other and go as far as the
+budget allows:
 
-<img src="https://labs.riseup.net/code/attachments/download/1837/scope.png">
+1. Unlocking partitions
+2. Unlocking file containers
+3. Creating and modifying partitions and containers
+4. *VeraCrypt Mounter*
 
-XXX: Fix this to mention iterations instead because the current
-structure is misleading:
-
-1. Partitions
-2. File containers
-3. Modification and creation
-4. Integration improvements
+The details of each iteration is in our
+[[blueprint|blueprint/veracrypt#scope]].
 
 ### Paper prototyping