Rename to Octokit to be consistent with other API libs

GitHub is naming all of the libraries Octokit for their respective
platforms

Octokit/Helpers/StringExtensions.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Globalization;
+
+namespace Octokit
+{
+    internal static class StringExtensions
+    {
+        public static bool IsBlank(this string value)
+        {
+            return string.IsNullOrWhiteSpace(value);
+        }
+
+        public static bool IsNotBlank(this string value)
+        {
+            return !string.IsNullOrWhiteSpace(value);
+        }
+
+        public static Uri FormatUri(this string pattern, params object[] args)
+        {
+            return new Uri(string.Format(CultureInfo.InvariantCulture, pattern, args), UriKind.Relative);
+        }
+
+        // :trollface:
+        [SuppressMessage("Microsoft.Globalization", "CA1308:NormalizeStringsToUppercase",
+            Justification = "Ruby don't care. Ruby don't play that.")]
+        public static string ToRubyCase(this string propertyName)
+        {
+            Ensure.ArgumentNotNullOrEmptyString(propertyName, "s");
+            return string.Join("_", propertyName.SplitUpperCase()).ToLowerInvariant();
+        }
+
+        static IEnumerable<string> SplitUpperCase(this string source)
+        {
+            Ensure.ArgumentNotNullOrEmptyString(source, "source");
+
+            int wordStartIndex = 0;
+            var letters = source.ToCharArray();
+            var previousChar = char.MinValue;
+
+            // Skip the first letter. we don't care what case it is.
+            for (int i = 1; i < letters.Length; i++)
+            {
+                if (char.IsUpper(letters[i]) && !char.IsWhiteSpace(previousChar))
+                {
+                    //Grab everything before the current character.
+                    yield return new String(letters, wordStartIndex, i - wordStartIndex);
+                    wordStartIndex = i;
+                }
+                previousChar = letters[i];
+            }
+
+            //We need to have the last word.
+            yield return new String(letters, wordStartIndex, letters.Length - wordStartIndex);
+        }
+    }
+}