Bunch of minor fixes and improvements

* removed some unused methods
* fix two issues with cut points, may or may not actually fix anything
* reduce lock scope in some methods to avoid stalling the connection for too long
* fix some recursive locking in CHTSPVFS
* made sure the connection mutex is always locked if SendAndWait() is called
* log "error:none" instead of "error:" when retrieving recordings, at least one user (myself not including) has been fooled into thinking something's wrong