Update VisualStudio.gitignore

Fixed pattern for excluding nuget packages so that it works both for top level package folder and for any lower level package folders.  Re-include patterns fixed the same way.

VisualStudio.gitignore

@@ -132,16 +132,19 @@ publish/
 
 # NuGet Packages
 packages/*
+**/packages/*
 *.nupkg
-## TODO: If the tool you use requires repositories.config
-## uncomment the next line
+## TODO: If the tool you use *requires* repositories.config, (note that this file is normally regenerated so you should not need it in source control)
+## uncomment the next two lines
 #!packages/repositories.config
+#!**/packages/repositories.config
 
 # Enable "build/" folder in the NuGet Packages folder since
 # NuGet packages use it for MSBuild targets.
-# This line needs to be after the ignore of the build folder
+# These two line needs to be after the ignore of the build folder
 # (and the packages folder if the line above has been uncommented)
 !packages/build/
+!**/packages/build/
 
 # Windows Azure Build Output
 csx/