make fields readonly where possible in EmuHawk project

src/BizHawk.Client.EmuHawk/CustomControls/FolderBrowserDialogEx.cs

@@ -22,7 +22,7 @@ namespace BizHawk.Client.EmuHawk
 	public sealed class FolderBrowserEx : Component
 	{
 		/// <remarks>is this supposed to be public? we're obviously not using it at callsites at the moment --yoshi</remarks>
-		private Win32Imports.BROWSEINFO.FLAGS publicOptions = Win32Imports.BROWSEINFO.FLAGS.RestrictToFilesystem | Win32Imports.BROWSEINFO.FLAGS.RestrictToDomain;
+		private readonly Win32Imports.BROWSEINFO.FLAGS publicOptions = Win32Imports.BROWSEINFO.FLAGS.RestrictToFilesystem | Win32Imports.BROWSEINFO.FLAGS.RestrictToDomain;
 
 		public string Description = "Please select a folder below:";
 

src/BizHawk.Client.EmuHawk/GraphicsImplementations/IGL_GdiPlus.cs

@@ -269,7 +269,7 @@ namespace BizHawk.Client.EmuHawk
 			{
 			}
 
-			private IGL_GdiPlus Gdi;
+			private readonly IGL_GdiPlus Gdi;
 
 			/// <summary>
 			/// the control associated with this render target (if any)

src/BizHawk.Client.EmuHawk/GraphicsImplementations/IGL_TK.cs

@@ -714,7 +714,7 @@ namespace BizHawk.Client.EmuHawk
 			//HAMNUTS:
 			//its not clear how many bindings we'll have to disable before we can enable the ones we need..
 			//so lets just disable the ones we remember we have bound
-			var currBindings = sVertexAttribEnables;
+			var currBindings = _sVertexAttribEnables;
 			foreach (var index in currBindings)
 				GL.DisableVertexAttribArray(index);
 			currBindings.Clear();
@@ -725,7 +725,7 @@ namespace BizHawk.Client.EmuHawk
 			UnbindVertexAttributes();
 
 			//HAMNUTS (continued)
-			var currBindings = sVertexAttribEnables;
+			var currBindings = _sVertexAttribEnables;
 			sStateCurrentVertexLayout = sStatePendingVertexLayout;
 
 			if (layout == null) return;
@@ -815,13 +815,13 @@ namespace BizHawk.Client.EmuHawk
 		private int sActiveTexture;
 		private VertexLayout sStateCurrentVertexLayout;
 		private VertexLayout sStatePendingVertexLayout;
-		private HashSet<int> sVertexAttribEnables = new HashSet<int>();
+		private readonly HashSet<int> _sVertexAttribEnables = new HashSet<int>();
 
 		private void PurgeStateCache()
 		{
 			sStateCurrentVertexLayout = null;
 			sStatePendingVertexLayout = null;
-			sVertexAttribEnables.Clear();
+			_sVertexAttribEnables.Clear();
 			sActiveTexture = -1;
 		}
 	

src/BizHawk.Client.EmuHawk/Sound/Output/OpenALSoundOutput.cs

@@ -147,8 +147,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private class BufferPool : IDisposable
 		{
-			private Stack<BufferPoolItem> _availableItems = new Stack<BufferPoolItem>();
-			private Queue<BufferPoolItem> _obtainedItems = new Queue<BufferPoolItem>();
+			private readonly Stack<BufferPoolItem> _availableItems = new Stack<BufferPoolItem>();
+			private readonly Queue<BufferPoolItem> _obtainedItems = new Queue<BufferPoolItem>();
 
 			public void Dispose()
 			{

src/BizHawk.Client.EmuHawk/config/FileExtensionPreferencesPicker.cs

@@ -9,7 +9,7 @@ namespace BizHawk.Client.EmuHawk
 {
 	public partial class FileExtensionPreferencesPicker : UserControl
 	{
-		private IDictionary<string, string> _preferredPlatformsForExtensions;
+		private readonly IDictionary<string, string> _preferredPlatformsForExtensions;
 
 		public FileExtensionPreferencesPicker(IDictionary<string, string> preferredPlatformsForExtensions)
 		{

src/BizHawk.Client.EmuHawk/config/N64/N64VideoPluginconfig.cs

@@ -38,7 +38,7 @@ namespace BizHawk.Client.EmuHawk
 			CustomResItemName
 		};
 
-		private bool _programmaticallyChangingPluginComboBox = false;
+		private readonly bool _programmaticallyChangingPluginComboBox = false;
 
 		public N64VideoPluginConfig(
 			IMainFormForConfig mainForm,

src/BizHawk.Client.EmuHawk/tools/Lua/LuaAutocompleteInstaller.cs

@@ -57,8 +57,8 @@ namespace BizHawk.Client.EmuHawk
 			return File.Exists(exePath);
 		}
 
-		private string SublimeLuaPath = @"Sublime Text 2\Packages\Lua";
-		private string SublimeCompletionsFilename = "bizhawk.lua.sublime-completions";
+		private readonly string SublimeLuaPath = @"Sublime Text 2\Packages\Lua";
+		private readonly string SublimeCompletionsFilename = "bizhawk.lua.sublime-completions";
 
 		private bool IsBizLuaSublimeInstalled()
 		{
@@ -66,8 +66,8 @@ namespace BizHawk.Client.EmuHawk
 			return File.Exists(bizCompletions);
 		}
 
-		private string NotepadPath = "TODO";
-		private string NotepadAutoCompleteFileName = "TODO";
+		private readonly string NotepadPath = "TODO";
+		private readonly string NotepadAutoCompleteFileName = "TODO";
 
 		private bool IsBizLuaNotepadInstalled()
 		{

src/BizHawk.Client.EmuHawk/tools/SNES/SNESGraphicsDebugger.cs

@@ -203,7 +203,7 @@ namespace BizHawk.Client.EmuHawk
 		private SNESGraphicsDecoder gd;
 		private SNESGraphicsDecoder.ScreenInfo si;
 		private SNESGraphicsDecoder.TileEntry[] map;
-		private byte[,] spriteMap = new byte[256, 224];
+		private readonly byte[,] spriteMap = new byte[256, 224];
 		private SNESGraphicsDecoder.BGMode viewBgMode;
 
 		private void RegenerateData()

src/BizHawk.Client.EmuHawk/tools/TraceLogger.cs

@@ -53,7 +53,7 @@ namespace BizHawk.Client.EmuHawk
 		private StreamWriter _streamWriter;
 		private bool _splitFile;
 		private string _baseName;
-		private string _extension = ".log";
+		private readonly string _extension = ".log";
 		private int _segmentCount;
 		private ulong _currentSize;