fromCache switch applied to upstream master.

The SearchResults ThemedWebPart was calling GetLanguage on multiple ContentItems in different languages.  This method was getting the language from the cache in every situation, so it was returning the wrong cached language for some ContentItems. I added the fromCache switch and set to true by default so previous calls to GetLanguage would function the same. However, I set it to false when called from the SearchResults ThemedWebPart indicating I want to calculate the language for each ContentItem passed from SearchResults. This will ensure search results are returned only for the language of the current SearchResults HttpContext