Refactor DirectoryHelper

Rename TryDeleteDirectory(string, int, int, int) to DeleteDirectory(...) because this method can still throw exceptions and is not fully in line with the try-parse pattern. Introduce TryDeleteDirectory(string) : bool as a try-parse pattern-compliant option to delete directories recursively without throwing exceptions. Remove DeleteSubdirectories(string) method because it is not used anywhere. Use 'var' keyword consistently across all methods. Related to #980

Author: ThomasBarnekow

LibGit2Sharp.Tests/TestHelpers/DirectoryHelper.cs

@@ -15,6 +15,8 @@ public static class DirectoryHelper
 {"gitmodules",".gitmodules"},
 };
 
+privatestaticreadonlyType[]whitelist={typeof(IOException),typeof(UnauthorizedAccessException)};
+
 publicstaticvoidCopyFilesRecursively(DirectoryInfosource,DirectoryInfotarget)
 {
 // From http://stackoverflow.com/questions/58744/best-way-to-copy-the-entire-contents-of-a-directory-in-c/58779#58779
@@ -34,15 +36,6 @@ private static string Rename(string name)
 returntoRename.ContainsKey(name)?toRename[name]:name;
 }
 
-publicstaticvoidDeleteSubdirectories(stringparentPath)
-{
-string[]dirs=Directory.GetDirectories(parentPath);
-foreach(stringdirindirs)
-{
-DeleteDirectory(dir);
-}
-}
-
 publicstaticvoidDeleteDirectory(stringdirectoryPath)
 {
 // From http://stackoverflow.com/questions/329355/cannot-delete-directory-with-directory-deletepath-true/329502#329502
@@ -53,28 +46,26 @@ public static void DeleteDirectory(string directoryPath)
 return;
 }
 NormalizeAttributes(directoryPath);
-TryDeleteDirectory(directoryPath,maxAttempts:5,initialTimeout:16,timeoutFactor:2);
+DeleteDirectory(directoryPath,maxAttempts:5,initialTimeout:16,timeoutFactor:2);
 }
 
 privatestaticvoidNormalizeAttributes(stringdirectoryPath)
 {
-string[]files=Directory.GetFiles(directoryPath);
-string[]dirs=Directory.GetDirectories(directoryPath);
+string[]filePaths=Directory.GetFiles(directoryPath);
+string[]subdirectoryPaths=Directory.GetDirectories(directoryPath);
 
-foreach(stringfileinfiles)
+foreach(stringfilePathinfilePaths)
 {
-File.SetAttributes(file,FileAttributes.Normal);
+File.SetAttributes(filePath,FileAttributes.Normal);
 }
-foreach(stringdirindirs)
+foreach(stringsubdirectoryPathinsubdirectoryPaths)
 {
-NormalizeAttributes(dir);
+NormalizeAttributes(subdirectoryPath);
 }
 File.SetAttributes(directoryPath,FileAttributes.Normal);
 }
 
-privatestaticreadonlyType[]whitelist={typeof(IOException),typeof(UnauthorizedAccessException)};
-
-privatestaticvoidTryDeleteDirectory(stringdirectoryPath,intmaxAttempts,intinitialTimeout,inttimeoutFactor)
+privatestaticvoidDeleteDirectory(stringdirectoryPath,intmaxAttempts,intinitialTimeout,inttimeoutFactor)
 {
 for(intattempt=1;attempt<=maxAttempts;attempt++)
 {