Reference gitignore in solution

This change makes .gitignore viewable in snes9xw.sln. It also updates
the solution to be opened in Visual Studio 2017 by default. This doesn't
prevent it from being opened in VS15 for those not ready to make the
switch.

.gitignore

@@ -1,3 +1,19 @@
+# snes9x program-generated files
+win32/snes9x.conf
+win32/Valid.Ext
+win32/stdout.txt
+win32/stderr.txt
+win32/Roms
+win32/Saves
+win32/Cheats
+win32/Screenshots
+win32/Movies
+win32/SPCs
+win32/BIOS
+
+# Included libraries in OS X that should not be ignored.
+!macosx/libz_u.a
+!macosx/libHIDUtilities_u.a
 
 # Created by https://www.gitignore.io/api/c,c++,visualstudio
 
@@ -360,16 +376,3 @@ __pycache__/
 *.xsd.cs
 
 # End of https://www.gitignore.io/api/c,c++,visualstudio
-
-# snes9x program-generated files
-win32/snes9x.conf
-win32/Valid.Ext
-win32/stdout.txt
-win32/stderr.txt
-win32/Roms
-win32/Saves
-win32/Cheats
-win32/Screenshots
-win32/Movies
-win32/SPCs
-win32/BIOS

win32/snes9xw.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.25420.1
+# Visual Studio 15
+VisualStudioVersion = 15.0.26228.9
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "Snes9X", "snes9xw.vcxproj", "{B86059D8-C9A6-46BE-8FBA-3170C54F1DFD}"
 EndProject
@@ -9,6 +9,11 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "libpng", "libpng\libpng.vcx
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "zlib", "zlib\zlib.vcxproj", "{99E9817A-4605-44AF-8433-7048F0EC1859}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{CF69CC6C-E1F2-41C3-A82C-D9C58127DD98}"
+	ProjectSection(SolutionItems) = preProject
+		..\.gitignore = ..\.gitignore
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug Unicode|Win32 = Debug Unicode|Win32