Fix the increment of InputNumber when the value is a string

src/domain_abstract/ui/InputNumber.js

@@ -102,7 +102,7 @@ module.exports = Input.extend({
     const model = this.model;
     this.getInputEl().value = model.get('value');
     const unitEl = this.getUnitEl();
-    unitEl && (unitEl.value = model.get('unit'));
+    unitEl && (unitEl.value = model.get('unit') || '');
   },
 
 
@@ -139,7 +139,7 @@ module.exports = Input.extend({
   upArrowClick() {
     const model = this.model;
     const step = model.get('step');
-    let value  = model.get('value');
+    let value  = parseInt(model.get('value'), 10);
     value = this.normalizeValue(value + step);
     var valid = this.validateInputValue(value);
     model.set('value', valid.value);
@@ -153,7 +153,7 @@ module.exports = Input.extend({
   downArrowClick() {
     const model = this.model;
     const step = model.get('step');
-    const value  = model.get('value');
+    const value  = parseInt(model.get('value'), 10);
     const val = this.normalizeValue(value - step);
     var valid = this.validateInputValue(val);
     model.set('value', valid.value);

src/trait_manager/model/Trait.js

@@ -8,6 +8,8 @@ module.exports = require('backbone').Model.extend({
     name: '',
     min: '',
     max: '',
+    unit: '',
+    step: 1,
     value: '',
     target: '',
     default: '',