better defaults for chained actions when there is no args/captureargs

[jjn1056]

https://gist.github.com/jjn1056/a455d0cf857871c40ab8

Currently if an action midpoint lacks captureargs, it becomes an end point as in the above gist, where the Args is presumed ... so these midpoints become both midpoints AND endpoints

Any true endpoint without a Args declaration is presumed Args (...)

even odder, if an action in a chain does do Args(1) and then another action chains off it, it becomes a CaptureArgs(0) midpoint.

Maybe we like this?