Fixes WPF text blurry render encountered in some cases.

[xjpo]

This fixes "blurry" text rendering in the WPF GraphicsAdapter.
I encountered this issue in the following cases:

• HtmlPanel embedded in Tooltip
• HtmlPanel used in ItemTemplate

The changes in this PR fixe my issues, but I haven't performed further testing. Any help from the community would be much appreciated.

My fix has greatly been inspired by this post : http://wpftutorial.net/DrawOnPhysicalDevicePixels.html. Might be usefull for the review.

[Licshee]

hmmmm... interesting, i'll look into this

[Licshee]

looks good to me

[AistisT]

This sadly makes everything blurry, just try out demo, difference is quite visible, though I am facing same issue as the op, with blurry text when having bunch of html object following each other, say items control or just manually declared

[neslekkim]

I reverted this change, and the text is not blurry anymore, so with this change, it's foggy, and I feel slight nausea when trying to read/focus on the text.
I host the control in an wpf usercontrol, inside an empty grid, would be interresting to see how to reproduce the original blurryness..

[AistisT]

have 3-4 web controls together displaying line or two of html/text, if you were displaying a loop of html encoded strings, middles ones will be blurry, this was attempting to fix that, but it was abad fix

[Licshee]

reverted, seems that it would take longer time for us to figure out a proper fix

[xjpo]

Hi,

I finally got the time to get back on this "blurry" issue, after this failed attempt to fix it...
Like some people here, several users of mine reported me issues on different setups.
I saw that @RachamimYaakobov proposed a fix here: #105, and it seems to be working just fine ! The solution is way simpler than I though !

@neslekkim, @AistisT you might want to try this fix.