Handle pending changes for contributions

This adds the pending tx data to pending contributions (after adding or
vetoing, until the tx is mined). It also disables the veto button while
pending.

app/services/kredits.js

@@ -225,6 +225,7 @@ export default Service.extend({
         console.debug('[kredits] add contribution response', data);
         attributes.contributor = this.contributors.findBy('id', attributes.contributorId);
         const contribution = Contribution.create(attributes);
+        contribution.set('pendingTx', data);
         contribution.set('confirmedAtBlock', data.blockNumber + 40320);
         this.contributions.pushObject(contribution);
         return contribution;
@@ -278,10 +279,12 @@ export default Service.extend({
 
   veto (contributionId) {
     console.debug('[kredits] veto against', contributionId);
+    const contribution = this.contributions.findBy('id', contributionId);
 
     return this.kredits.Contribution.functions.veto(contributionId, { gasLimit: 300000 })
       .then(data => {
         console.debug('[kredits] veto response', data);
+        contribution.set('pendingTx', data);
         return data;
       });
   },
@@ -367,6 +370,7 @@ export default Service.extend({
 
     if (contribution) {
       contribution.set('vetoed', true);
+      contribution.set('pendingTx', null);
     }
   },