Khmer language text is cutted in TextLabel.

Khmer language text is cutted in TextLabel.

* Fixed an issue while retrieving the 'width' metric from complex glyphs.
  i.e the complex glyph 'ត់' is formed by two glyphs ( 'ត' and '់')
  The width of the group is calculated as the accumulated advance + the
  x bearing and width of the last glyph. In that case for the last glyph
  the accumulated advance plus the width is smaller than the width of the
  previous glyph.

* The solution is to calculate the initial width edge and the max width edge.

if HORIZONTAL_ALIGNMENT is END, this is a problem.
example)
    TextLabel labe21 = TextLabel::New();
    labe21.SetSize( 600, 100 );
    labe21.SetParentOrigin(ParentOrigin::TOP_LEFT);
    labe21.SetAnchorPoint(AnchorPoint::TOP_LEFT);
    labe21.SetPosition( 100.f, 100.f);
    labe21.SetProperty( TextLabel::Property::HORIZONTAL_ALIGNMENT, "END" );
    labe21.SetProperty(Dali::Toolkit::TextLabel::Property::TEXT, "ការកំណត់" );
    stage.Add( labe21 );

Change-Id: I0a59ddc0c2c01493ea381f50310882ca9dcfc2e9