Implemented "Do Not Show Again" check boxes using HTML5 local storage.
Previewed Layers table is now sorted by reverse z-axis index as the
previewed layer appears on the map. (top layer in the table is top layer
on the map, etc.)
-added init directive to httpClient.pooling bean so that the HttpClient
Connection Manager initialization is not lazy. (some initial response
latency issues)
-removed logging for credential info in PoolingHttpClient (was for
debugging)
-fixed a bug in the download javascript/template.  The "clip to extent"
checkbox value was not being transmitted to the request object.
bugfix in download code. wrong context in an anonymous function.
Merge pull request #17 from chrissbarnett/preview_zorder

Preview zorder, do not show again