Allow GetTexture calls with no second value in the range header (e.g. just 5333-)

It looks like the latest Kokua is doing this.
As per http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html, leaving off the second value is legal
This indicates the caller wants the rest of the entity.

OpenSim/Capabilities/Handlers/GetTexture/GetTextureHandler.cs

@@ -246,6 +246,11 @@ namespace OpenSim.Capabilities.Handlers
                     }
                     else
                     {
+                        // Handle the case where no second range value was given.  This is equivalent to requesting
+                        // the rest of the entity.
+                        if (end == -1)
+                            end = int.MaxValue;
+
                         end = Utils.Clamp(end, 0, texture.Data.Length - 1);
                         start = Utils.Clamp(start, 0, end);
                         int len = end - start + 1;
@@ -299,16 +304,44 @@ namespace OpenSim.Capabilities.Handlers
 //                    texture.FullID, range, response.StatusCode, response.ContentLength, texture.Data.Length);
         }
 
+        /// <summary>
+        /// Parse a range header.
+        /// </summary>
+        /// <remarks>
+        /// As per http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html,
+        /// this obeys range headers with two values (e.g. 533-4165) and no second value (e.g. 533-).
+        /// Where there is no value, -1 is returned.
+        /// FIXME: Need to cover the case where only a second value is specified (e.g. -4165), probably by returning -1
+        /// for start.</remarks>
+        /// <returns></returns>
+        /// <param name='header'></param>
+        /// <param name='start'>Undefined if the parse fails.</param>
+        /// <param name='end'>Undefined if the parse fails.</param>
         private bool TryParseRange(string header, out int start, out int end)
         {
+            start = end = 0;
+
             if (header.StartsWith("bytes="))
             {
                 string[] rangeValues = header.Substring(6).Split('-');
+
                 if (rangeValues.Length == 2)
                 {
-                    if (Int32.TryParse(rangeValues[0], out start) && Int32.TryParse(rangeValues[1], out end))
+                    if (!Int32.TryParse(rangeValues[0], out start))
+                        return false;
+
+                    string rawEnd = rangeValues[1];
+
+                    if (rawEnd == "")
+                    {
+                        end = -1;
                         return true;
                     }
+                    else if (Int32.TryParse(rawEnd, out end))
+                    {
+                        return true;
+                    }
+                }
             }
 
             start = end = 0;