Update thirdparty submodule.
Merge branch 'bugfix-12294' into release-6.6.2
[[ Bug 11748 ]] If replacing XML text node contents with empty, then just discard text nodes (don't try to insert a new one).
[[ Bug 12210 ]] Update revBrowser on Windows to use a different snapshot method from before (old one doesn't work in IE9+).
Merge branch 'bugfix-11748' into release-6.6.2
[[ Bug 11748 ]] Added release note.
Merge branch 'bugfix-12210' into release-6.6.2
[[ Bug 12173 ]] Styling does not work for certain iOS fonts.
[[ Bug 12350 ]] The fontStyles is incorrect on iOS.
[[ Bug 12265 ]] Rounded rects are drawn incorrectly when using the image editing tools with a linesize 1.
Merge branch 'bugfix-12173-12350' into release-6.6.2
Updated version to 6.6.2-rc-3.
[[ Bug 12044 ]] Fix incomplete rendering of opaque group background when acceleratedRendering is enabled
Revert "[[ Bug 12044 ]] Fix incomplete rendering of opaque group background when acceleratedRendering is enabled"

This reverts commit 8e230bc8ff161b3e4efe390d09e728068e5e82e7.
[[ Bug 12044 ]] Reimplement fix by disabling scrolling layer mode for opaque groups with overscroll or patterned backgrounds
Merge branch 'bugfix-12044_rebase' into release-6.6.2
[[ Bug 12319 ]] Convert drag & drop coords to logical
Merge branch 'bugfix-12319' into release-6.6.2
[[ Bug 12294 ]] Further tweaks after discovery of more logical errors.