fixed issue when binded lower value can become smaller than its inner copy.
Merge pull request #1349 from QuantumDeveloper/RangeSlider

RangeSlider [Hotfix]: fixed issue when binded lower value can become smaller than its inner copy
fix passwordbox watermark if password is set
Merge pull request #1353 from MahApps/1343-punker76-passwordbox-watermark-bug

fix passwordbox watermark if password is set
Merge pull request #1347 from badbredren/master

#1346 Add Behavior for TabControls to select the first visible TabItem