Replace primary usages

Author: bording

LibGit2Sharp/Core/Proxy.cs

@@ -2793,7 +2793,7 @@ public static unsafe SignatureHandle git_signature_new(string name, string email
         {
             git_signature* ptr;
 
-            int res = NativeMethods.git_signature_new(out ptr, name, email, when.ToSecondsSinceEpoch(),
+            int res = NativeMethods.git_signature_new(out ptr, name, email, when.ToUnixTimeSeconds(),
                                                       (int)when.Offset.TotalMinutes);
             Ensure.ZeroResult(res);
 

LibGit2Sharp/Core/TarWriter.cs

@@ -332,7 +332,7 @@ public UsTarHeader(
 
                 this.mode = Convert.ToString(mode, 8).PadLeft(7, '0');
                 this.size = size;
-                unixTime = Convert.ToString(lastModificationTime.ToSecondsSinceEpoch(), 8).PadLeft(11, '0');
+                unixTime = Convert.ToString(lastModificationTime.ToUnixTimeSeconds(), 8).PadLeft(11, '0');
                 this.userId = userId.PadLeft(7, '0');
                 this.groupId = userId.PadLeft(7, '0');
                 this.userName = userName;

LibGit2Sharp/Signature.cs

@@ -21,7 +21,7 @@ internal unsafe Signature(git_signature* sig)
         {
             name = LaxUtf8Marshaler.FromNative(sig->name);
             email = LaxUtf8Marshaler.FromNative(sig->email);
-            when = Epoch.ToDateTimeOffset(sig->when.time, sig->when.offset);
+            when = DateTimeOffset.FromUnixTimeSeconds(sig->when.time).ToOffset(TimeSpan.FromMinutes(sig->when.offset));
         }
 
         /// <summary>