Some libraries use `application/json; charset=utf-8` as their `Content-Type`, which is valid.
However we were not decoding the JSON body in that case, resulting in issues communicating with the rcserver.
* Lower pacer minSleep to establish new connections faster
* Use Echo requests to check whether connections are working (required an upgrade of go-smb2)
* Only remount shares when needed
* Use context for connection establishment
* When returning a connection to the pool, only check the ones that encountered errors
* Close connections in parallel
Jonathan GiannuzziandNick Craig-Wood