wrap potentially large pages in a flickable, for small form factors

electrum/gui/qml/components/WizardComponents.qml

@@ -137,7 +137,14 @@ Item {
                 warningtext.text = t.join("")
             }
 
+            Flickable {
+                anchors.fill: parent
+                contentHeight: mainLayout.height
+                clip:true
+                interactive: height < contentHeight
+
                 GridLayout {
+                    id: mainLayout
                     width: parent.width
                     columns: 1
 
@@ -174,6 +181,7 @@ Item {
                         bitcoin.generate_seed()
                     }
                 }
+            }
 
             Bitcoin {
                 id: bitcoin
@@ -222,7 +230,14 @@ Item {
                 infotext.text = t[seed_type.currentText]
             }
 
+            Flickable {
+                anchors.fill: parent
+                contentHeight: mainLayout.height
+                clip:true
+                interactive: height < contentHeight
+
                 GridLayout {
+                    id: mainLayout
                     width: parent.width
                     columns: 2
 
@@ -265,6 +280,7 @@ Item {
                         echoMode: TextInput.Password
                     }
                 }
+            }
 
             Bitcoin {
                 id: bitcoin
@@ -285,7 +301,14 @@ Item {
                 valid = seedvalid && (wizard_data['seed_extend'] ? customwordsvalid : true)
             }
 
+            Flickable {
+                anchors.fill: parent
+                contentHeight: mainLayout.height
+                clip:true
+                interactive: height < contentHeight
+
                 GridLayout {
+                    id: mainLayout
                     width: parent.width
                     columns: 1
 
@@ -313,6 +336,7 @@ Item {
                         }
                     }
                 }
+            }
 
             onReadyChanged: {
                 if (ready)