(MahAppsGH-3272) Fix Wrong FileVersion and AssemblyVersion for v1.6.4

Closes MahApps#3272

Merge pull request MahApps#3249 from MahApps/hotfix/GH-3248_Fix_thumb…

…_in_FlatSlider

(MahAppsGH-3248) fix thumb in FlatSlider

Merge pull request MahApps#3246 from MahApps/develop

Merging changes for v1.6.3

Merge pull request MahApps#3232 from MahApps/develop

Merging changes for v1.6.2

Merge pull request MahApps#3204 from MahApps/develop

Merging changes for v1.6.1

Fix NuGet release version

Merge pull request MahApps#3091 from MahApps/feature/3010_HamburgerMe…

…nu_TabStop

Fix MahApps#3010 IsTabStop for HamburgerMenu

Watermark fixes and improvements (MahApps#3069)

* Fix right aligned floating Watermark

* Use TextBoxHelper.Watermark for HotKeyBox
  instead own DependencyProperty
Allow AutoWatermark for HotKey DependencyProperty

* New TextBoxHelper.WatermarkTrimming attached property
  to set the text trimming behavior to employ when watermark overflows the content area.

* New TextBoxHelper.WatermarkWrapping attached property
  (only for TextBox) to set how the watermark should wrap text. Default is binded to TextWrapping property.

* Update 1.6.0.md

appveyor ... $env:

Set v1.5.0.23

  and update NuGet.exe