Fixes tests crashing due to UI thread not being initialized. Fixes MockTrackingSpan not correctly rewinding changes.
Fixes tests crashing due to UI thread not being initialized.
Fixes MockTrackingSpan not correctly rewinding changes.

Microsoft/VisualStudio-SharedProject,enricosada/VisualStudio-SharedProject,mousetraps/xtvs-common,mousetraps/xtvs-common