adjustments to failDate

* It only gets used in a class method, so it doesn’t need to be an
iVar. It’s declared locally.
* Made it static
* Sync the timeout for failure with the default proxy cache time.
They’re not the same thing, but they should both be updated as hardware
gets faster.
make Current Selection more efficient

* only get information for the current application once
* alter the order when getting types: types from plist, fallback to
string, types from provider → types from provider, types from plist,
fallback to string
* eliminate the poorly named passthroughProxyInfo class method