[RFC] clear type stuff

[punker76]

ClearType partially not working, so this pr should fix some of it

• TextBox ignores ClearType
• ComboBox and Menu popup ignores ClearType
  • fix ComboBox ClearType
  • set the correct Effect to enable ClearType (for ComboBox)
  • fix Menu ClearType
  • maybe another Controls too

Benefit

• we got a ClearType enabled ui

Side effect

• if we set AllowTransparency="False" for popups, we lost the popup animation, so don't do it :-D

Guidlines, if the user wants clearer text

• inherite from default style and add this lines

    <Style TargetType="ComboBoxItem"
           BasedOn="{StaticResource MetroComboBoxItem}"
           x:Key="ClearMetroComboBoxItem">
        <Setter Property="TextOptions.TextRenderingMode"
                Value="ClearType" />
        <Setter Property="TextOptions.TextFormattingMode"
                Value="Display" />
    </Style>

Scenarios	Recommended Mode
Large Text (15pt+)	Ideal \ Display (users preference)
Transformed Text	Ideal
Zoomed Text	Ideal
Design Scenarios	Ideal
Small Text	Display

Closes #1536

[punker76]

@BerndK @mahara testable now...