+PTYs
+
+Need support for toggling echo and line buffering
+- This needs to be communicated to pty owner somehow
+ > Second FD? Nominated data structure? Out of band data?
+- API for the pty control?
+ > "_SysSetFileFlag"/"_SysGetFileFlag"?
+ Provides arbitary flags for each node
+ E.g. Terminal graphics mode, echo and buffering