Nuget - chromiumembeddedframework.runtime add .props files to build folder

previously only buildTransitive was supported.

Issue #93

Author: amaitland

NuGet/chromiumembeddedframework.runtime.win.nuspec

@@ -27,6 +27,7 @@
     <file src="..\cef_binary_3.y.z_$CPlatform$\Resources\*.pak" target="runtimes\win-$Platform$\native\"/>
     <file src="..\cef_binary_3.y.z_$CPlatform$\Resources\*.dat" target="runtimes\win-$Platform$\native\"/>
     <file src="..\cef_binary_3.y.z_$CPlatform$\Readme.txt" target="\"/>
+	<file src="chromiumembeddedframework.runtime.win-$Platform$.props" target="build\" />
 	<file src="chromiumembeddedframework.runtime.win-$Platform$.props" target="buildTransitive\" />
 
 	<!-- Architecture-specific files folder hierarchy lost (native subfolders)  -->