fix(button): remove classes from buttons with categories

references #6237

Author: brandyscarney

ionic/components/action-sheet/action-sheet.ts

@@ -222,14 +222,14 @@ export class ActionSheet extends ViewController {
         '<div class="action-sheet-group">' +
           '<div class="action-sheet-title" id="{{hdrId}}" *ngIf="d.title">{{d.title}}</div>' +
           '<div class="action-sheet-sub-title" id="{{descId}}" *ngIf="d.subTitle">{{d.subTitle}}</div>' +
-          '<button category="action-sheet-button" (click)="click(b)" *ngFor="#b of d.buttons" class="action-sheet-button disable-hover" [ngClass]="b.cssClass">' +
+          '<button category="action-sheet-button" (click)="click(b)" *ngFor="#b of d.buttons" class="disable-hover" [ngClass]="b.cssClass">' +
             '<ion-icon [name]="b.icon" *ngIf="b.icon" class="action-sheet-icon"></ion-icon> ' +
             '{{b.text}}' +
             '<ion-button-effect></ion-button-effect>' +
           '</button>' +
         '</div>' +
         '<div class="action-sheet-group" *ngIf="d.cancelButton">' +
-          '<button category="action-sheet-button" (click)="click(d.cancelButton)" class="action-sheet-button action-sheet-cancel disable-hover" [ngClass]="d.cancelButton.cssClass">' +
+          '<button category="action-sheet-button" (click)="click(d.cancelButton)" class="action-sheet-cancel disable-hover" [ngClass]="d.cancelButton.cssClass">' +
             '<ion-icon [name]="d.cancelButton.icon" *ngIf="d.cancelButton.icon" class="action-sheet-icon"></ion-icon> ' +
             '{{d.cancelButton.text}}' +
             '<ion-button-effect></ion-button-effect>' +

ionic/components/alert/alert.ts

@@ -353,7 +353,7 @@ export class Alert extends ViewController {
 
       '</div>' +
       '<div class="alert-button-group" [ngClass]="{vertical: d.buttons.length>2}">' +
-        '<button category="alert-button" *ngFor="#b of d.buttons" (click)="btnClick(b)" [ngClass]="b.cssClass" class="alert-button">' +
+        '<button category="alert-button" *ngFor="#b of d.buttons" (click)="btnClick(b)" [ngClass]="b.cssClass">' +
           '{{b.text}}' +
           '<ion-button-effect></ion-button-effect>' +
         '</button>' +

ionic/components/navbar/navbar.ts

@@ -91,7 +91,7 @@ class ToolbarBackground {
   selector: 'ion-navbar',
   template:
     '<div class="toolbar-background"></div>' +
-    '<button class="back-button bar-button bar-button-default" [hidden]="_hideBb">' +
+    '<button category="bar-button" class="back-button" [hidden]="_hideBb">' +
       '<span class="button-inner">' +
         '<ion-icon class="back-button-icon" [name]="_bbIcon"></ion-icon>' +
         '<span class="back-button-text">' +