rework key view into fragments to later add certifications

OpenPGP-Keychain/src/main/res/layout/view_key_userids_item.xml

@@ -1,16 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="?android:attr/listPreferredItemHeight"
-    android:layout_marginRight="?android:attr/scrollbarSize"
+    android:layout_height="wrap_content"
     android:orientation="vertical"
-    android:singleLine="true" >
+    android:paddingRight="3dip"
+    android:singleLine="true">
 
     <TextView
         android:id="@+id/userId"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:paddingRight="3dip"
         android:text="User ID"
         android:textAppearance="?android:attr/textAppearanceSmall" />