Minor, hide scordature for non guitar, missing color dialog titles

src/qml/MainScore.qml

 /** This file is part of Nootka (http://nootka.sf.net)               *
- * Copyright (C) 2017 by Tomasz Bojczuk (seelook@gmail.com)          *
+ * Copyright (C) 2017-2018 by Tomasz Bojczuk (seelook@gmail.com)     *
  * on the terms of GNU GPLv3 license (http://www.gnu.org/licenses)   */
 
 import QtQuick 2.9
@@ -118,7 +118,7 @@ Score {
       scordature.destroy()
       scordature = null
     }
-    if (GLOB.tuning.scordature && GLOB.instrument.type !== Tinstrument.BassGuitar) {
+    if (GLOB.tuning.scordature && GLOB.instrument.isGuitar && GLOB.instrument.type !== Tinstrument.BassGuitar) {
         var c = Qt.createComponent("qrc:/score/Scordature.qml")
         scordature = c.createObject(firstStaff)
         firstStaff.scordSpace = scordature.height

src/qml/settings/InstrumentPage.qml

@@ -177,7 +177,7 @@ Flickable {
         spacing: Noo.fontSize()
         anchors.horizontalCenter: parent.horizontalCenter
         Text { color: activPal.text; text: qsTr("color of a pointer on an instrument"); anchors.verticalCenter: parent.verticalCenter }
-        ColorButton { id: fingerColorButt; color: GLOB.fingerColor }
+        ColorButton { id: fingerColorButt; color: GLOB.fingerColor; title: qsTr("color of a pointer on an instrument") }
       }
     }
     Tile {
@@ -185,7 +185,7 @@ Flickable {
         spacing: Noo.fontSize()
         anchors.horizontalCenter: parent.horizontalCenter
         Text { color: activPal.text; text: qsTr("color of a selection"); anchors.verticalCenter: parent.verticalCenter }
-        ColorButton { id: selectedColorButt; color: GLOB.selectedColor }
+        ColorButton { id: selectedColorButt; color: GLOB.selectedColor; title: qsTr("color of a selection") }
       }
     }
     Component.onCompleted: { // to avoid declaring every property signal in Tglobals.h