Fix style manager with rules containing !important. Closes #4719

src/style_manager/model/Property.js

@@ -362,7 +362,7 @@ export default class Property extends Model {
    * @return {string}
    * @private
    */
-  getFullValue(val) {
+  getFullValue(val, opts = {}) {
     const fn = this.get('functionName');
     const def = this.getDefaultValue();
     let value = isUndefined(val) ? this.get('value') : val;
@@ -377,7 +377,7 @@ export default class Property extends Model {
       value = `${fn}(${fnParameter})`;
     }
 
-    if (hasValue && this.get('important')) {
+    if (hasValue && this.get('important') && !opts.skipImportant) {
       value = `${value} !important`;
     }
 

src/style_manager/view/PropertyView.js

@@ -127,7 +127,7 @@ export default class Property extends View {
   }
 
   onValueChange(m, val, opt = {}) {
-    this.setValue(this.model.getFullValue());
+    this.setValue(this.model.getFullValue(undefined, { skipImportant: true }));
     this.updateStatus();
   }