Views filter uses '_none' instead of 'All'

The empty option for cshs dropdowns in Views exposed filters is "_none". This is causing problems for me as I am redirecting the submission of another View (with a standard taxonomy drop-down listing, not cshs) to my cshs enabled view. However it is standard for Views taxonomy drop-downs to have an empty option of "All". My redirection then gives me an "illegal value has been selected" type error as a result.

While my redirection is kinda custom, I would expect cshs to use "All" rather than "_none" for views exposed filter drop-downs. If you think about it a bit, we have a views exposed filter on a taxonomy, which if not completed returns all nodes regardless of their tag. It doesn't return nodes that have no tags applied. Logically the naming convention doesn't make sense.

My attached patch changes the empty value definition. This might also affect entity field widgets perhaps... where a value of "_none" might make more sense to be fair. However, this patch is just to get the conversation started and if you're willing to accept this change, we can look at supporting both scenarios fully.