Required filed should have an asterisk inside the label (#1776)

ng2-components/ng2-activiti-form/src/components/widgets/amount/amount.widget.html

@@ -1,6 +1,6 @@
 <div class="mdl-textfield mdl-js-textfield amount-widget {{field.className}}"
      [class.amount-widget__invalid]="!field.isValid">
-    <label [attr.for]="field.id">{{field.name}}, {{currency}}</label>
+    <label [attr.for]="field.id">{{field.name}}, {{currency}}<span *ngIf="isRequired()">*</span></label>
     <input class="mdl-textfield__input"
            type="text"
            [attr.id]="field.id"

ng2-components/ng2-activiti-form/src/components/widgets/attach/attach.widget.html

@@ -1,5 +1,5 @@
 <div class="attach-widget {{field.className}}">
-    <label [attr.for]="field.id">{{field.name}}</label>
+    <label [attr.for]="field.id">{{field.name}}<span *ngIf="isRequired()">*</span></label>
     <div>
         <span *ngIf="hasFile()" class="attach-widget__file mdl-chip"><span class="mdl-chip__text">{{getLinkedFileName()}}</span></span>
         <button #browseFile (click)="showDialog();" class="mdl-button mdl-js-button mdl-js-ripple-effect attach-widget__browser">

ng2-components/ng2-activiti-form/src/components/widgets/date/date.widget.html

@@ -2,7 +2,7 @@
     <div class="mdl-cell mdl-cell--11-col">
         <div class="mdl-textfield mdl-js-textfield date-widget"
              [class.date-widget__invalid]="!field.isValid">
-            <label [attr.for]="field.id">{{field.name}} ({{field.dateDisplayFormat}})</label>
+            <label [attr.for]="field.id">{{field.name}} ({{field.dateDisplayFormat}})<span *ngIf="isRequired()">*</span></label>
             <input class="mdl-textfield__input mdl-date__input"
                    type="text"
                    [attr.id]="field.id"

ng2-components/ng2-activiti-form/src/components/widgets/dropdown/dropdown.widget.html

@@ -1,6 +1,6 @@
 <div class="dropdown-widget {{field.className}}"
      [class.dropdown-widget__invalid]="!field.isValid" *ngIf="field?.isVisible">
-    <label class="dropdown-widget__label" [attr.for]="field.id">{{field.name}}</label>
+    <label class="dropdown-widget__label" [attr.for]="field.id">{{field.name}}<span *ngIf="isRequired()">*</span></label>
     <select class="dropdown-widget__select"
             [attr.id]="field.id"
             [(ngModel)]="field.value"

ng2-components/ng2-activiti-form/src/components/widgets/multiline-text/multiline-text.widget.html

@@ -1,6 +1,6 @@
 <div class="mdl-textfield mdl-js-textfield multiline-text-widget {{field.className}}"
      [class.multiline-text-widget__invalid]="!field.isValid">
-    <label [attr.for]="field.id">{{field.name}}</label>
+    <label [attr.for]="field.id">{{field.name}}<span *ngIf="isRequired()">*</span></label>
     <textarea class="mdl-textfield__input"
               type="text"
               rows= "3"

ng2-components/ng2-activiti-form/src/components/widgets/number/number.widget.html

@@ -1,6 +1,6 @@
 <div class="mdl-textfield mdl-js-textfield number-widget {{field.className}}"
      [class.number-widget__invalid]="!field.isValid">
-    <label [attr.for]="field.id">{{field.name}}</label>
+    <label [attr.for]="field.id">{{field.name}}<span *ngIf="isRequired()">*</span></label>
     <input class="mdl-textfield__input"
            type="text"
            pattern="-?[0-9]*(\.[0-9]+)?"

ng2-components/ng2-activiti-form/src/components/widgets/people/people.widget.html

@@ -1,6 +1,6 @@
 <div class="mdl-textfield mdl-js-textfield people-widget {{field.className}}"
      [class.people-widget__invalid]="!field.isValid">
-    <label [attr.for]="field.id">{{field.name}}</label>
+    <label [attr.for]="field.id">{{field.name}}<span *ngIf="isRequired()">*</span></label>
     <input class="mdl-textfield__input"
            type="text"
            [attr.id]="field.id"

ng2-components/ng2-activiti-form/src/components/widgets/radio-buttons/radio-buttons.widget.html

@@ -1,6 +1,6 @@
 <div class="radio-buttons-widget {{field.className}}"
      [class.radio-buttons-widget__invalid]="!field.isValid" [id]="field.id" *ngIf="field?.isVisible">
-    <label class="radio-buttons-widget__label" [attr.for]="field.id">{{field.name}}</label>
+    <label class="radio-buttons-widget__label" [attr.for]="field.id">{{field.name}}<span *ngIf="isRequired()">*</span></label>
     <div *ngFor="let opt of field.options">
         <label [id]="opt.id" [attr.for]="field.id + '-' + opt.id" class="mdl-radio mdl-js-radio">
             <input type="radio"

ng2-components/ng2-activiti-form/src/components/widgets/text/text.widget.html

@@ -1,6 +1,6 @@
 <div class="mdl-textfield mdl-js-textfield text-widget {{field.className}}"
      [class.text-widget__invalid]="!field.isValid">
-    <label [attr.for]="field.id">{{field.name}}</label>
+    <label [attr.for]="field.id">{{field.name}}<span *ngIf="isRequired()">*</span></label>
     <input class="mdl-textfield__input"
            type="text"
            [attr.id]="field.id"