* Rename 'Microsoft.WinFx.targets' to 'Microsoft.WinFX.targets'

'WinFX' is the correct casing as observed in the .NET CLR 2 frameworks

* Fix 'WinFx' -> 'WinFX' everywhere else

In project files, scripts, comments, etc...
But not in sources (like GetWinFxCallback)

* NewLine fixes for only previously changed files

Conforming to the repository's EditorConfig file
IN this Patch tree

* Update & Format EditorConfig

Add 'trim_trailing_whitespace' to EditorConfig

* Remove all trailing whitespaces

for only previously changed files (in this Patch tree)
Conforming to the repository's EditorConfig file

In project files, scripts, comments, etc...
But not in sources (like GetWinFxCallback)

The PresentationBuildTasks.dll built out of the .NET Core codebase is not being used for msbuild based builds (i.e., when `$(MSBuildRuntimeType)==Full`) of WPF projects that use WindowsDesktop SDK. Instead, the PresentationBuildTasks.dll from GAC, i.e., the DLL that shipped with .NET Framework, is being used for builds instead. (#2075)

This is because the *first* occurance of an `UsingTask` element that applies to a `TaskName` will always be used - it can not be overridden by subsequent `UsingTask` entries (this is unlike `Property` and `Item` behavior). See note in https://github.com/MicrosoftDocs/visualstudio-docs/blob/master/docs/msbuild/usingtask-element-msbuild.md immediate after the **Syntax** section (Note: The msbuild team added this note after identifying this behavior as part of investiaging this PresentationBuildTasks.dll issue).

The fix ensures that the `UsingTask` declarations supplied by the WindowsDesktop SDK precede those supplied by .NET Framework's copy of `Microsoft.WinFX.targets` by introducing a new `.props` file - `Microsoft.WinFX.props` - and moving a small number of `Property` and `UsingTask` declartions into it. Since `.props` are imported before `targets`, the `UsingTask` declarations supplied by WindowsDesktop SDK will thus take precedence.

The PresentationBuildTasks.dll built out of the .NET Core codebase is not being used for msbuild based builds (i.e., when `$(MSBuildRuntimeType)==Full`) of WPF projects that use WindowsDesktop SDK. Instead, the PresentationBuildTasks.dll from GAC, i.e., the DLL that shipped with .NET Framework, is being used for builds instead.

This is because the *first* occurance of an `UsingTask` element that applies to a `TaskName` will always be used - it can not be overridden by subsequent `UsingTask` entries (this is unlike `Property` and `Item` behavior). See note in https://github.com/MicrosoftDocs/visualstudio-docs/blob/master/docs/msbuild/usingtask-element-msbuild.md immediate after the **Syntax** section (Note: The msbuild team added this note after identifying this behavior as part of investiaging this PresentationBuildTasks.dll issue).

The fix ensures that the `UsingTask` declarations supplied by the WindowsDesktop SDK precede those supplied by .NET Framework's copy of `Microsoft.WinFX.targets` by introducing a new `.props` file - `Microsoft.WinFX.props` - and moving a small number of `Property` and `UsingTask` declartions into it. Since `.props` are imported before `targets`, the `UsingTask` declarations supplied by WindowsDesktop SDK will thus take precedence.

Define _WindowsDesktopSdkTargetFrameworkVersionFloor before  Microsoft.NET.Sdk.WindowsDesktop.targets is imported (#1077)

* Define _WindowsDesktopSdkTargetFrameworkVersionFloor before  Microsoft.NET.Sdk.WindowsDesktop.targets is imported

* Suppress NETSDK1106

Preview 4 branch snap into release/3.0 

Fallbacks for building internal WPF projects that use PresentationBuildTasks.dll and Microsoft.WinFX.targets for markup compilation (#485)

* Adding fallbacks for building WPF projects that use PresentationBuildTasks.dll and Microsoft.WinFX.targets for markup compilation

* Workaround for GenerateVersionFileWithRepositoryCommit target to ensure that version.txt is always generated correctly and embedded inside nupkg's

This PR onboards a new shared build infrastrucutre - primarily props + targets - that are shared between this repo and WPF's internal build.