Download Code checked in

This is also a few weeks late, I finished testing on the last weeks of my vacation in mid-July while still in Korea. The folks at WorldWindCentral were kind enough to provide me commit access to SVN, so I have started my own branch to check in the changes. So far this has not been commited to /trunk yet.

Here is the the URL for my shiny new SVN branch:
https://nasa-exp.svn.sourceforge.net/svnroot/nasa-exp/branches/ammianus

As far as the Download code I also I posted a detail list of the fixes I have done here:
http://worldwindcentral.com/wiki/1_4_1_Issues#Download_code_error_response_handling

Logical changes include new error response handling:
* 4xx / Client error are cached as failures and WW will not retry to download them during that session (cache is in memory only and cleared when WW is exited).

• 400 Bad Request


• 401 Unauthorized


• 403 Forbidden


• 404 Not Found


• 206 Partial Content


• 200 OK && Content length == 0

* 5xx / Server Error are recorded and a timeout period will begin before requests are allowed to this server again. A message is displayed in the top right of the UI stating the timeout length. If server response contains "retry-after" header, that period is used, otherwise default is 2 minutes.

• 500 Internal Server Error


• 501 Not Implemented


• 502 Bad Gateway


• 503 Service Unavailable

Changes made to source files:

* WebDownload/WebDownload.cs
* PluginSDK/QuadTileSet.cs
* PluginSDK/Renderable/GeoSpatialDownloadRequest.cs