autowaf has no real shutdown functionality anyway. The automatic
shutdown function that could have been called wouldn't work anyway, as
it takes an argument.
The only reason it doesn't fail is that the top level wscript has no
shutdown handling and doesn't recurse to other scripts, so it is all
dead code.
Variables by these names are only used from the local wscript and when
running "waf configure", which already for other reasons only can run at
the top-level.
These variables are thus not mandatory and not used.
Terminology used by server and client was starting to diverge.
C++ classes ArdourStrips and ArdourGlobals classes have been
renamed to ArdourMixer and ArdourTransport respectively.
State node values for transport functionality have been simplified
and prefixed with 'transport_' to match what was done for strips.