[Dev] Heads up: osaf.startup to replace osaf.framework.wakeup and TwistedReactorManager

[Phillip J. Eby]

FYI, I'm about to replace the TwistedReactorManager and the 
osaf.framework.wakeup parcel with the features offered by osaf.startup, 
which encompasses all types of startup items including:

Startup - run some code when Chandler starts
Thread  - run some code in a thread when Chandler starts
TwistedTask - run some code in the reactor thread when Chandler starts
PeriodicTask - like wakeupCaller, but a bit simpler to use and more flexible

Each of these kinds accepts an "invoke" parameter that's a string naming 
the thing to import and run.  There is detailed documentation and examples 
on the use of these features in parcels/osaf/startups.txt.

In my current checkout, I've replaced all WakeupCaller items with 
PeriodicTask objects that do the same things, and changed 
application.Utility to call the new run_startup() and 
start_reactor()/stop_reactor() APIs.  Ted and I are doing some testing to 
make sure everything works right, and then I'll commit this.

I think I've spoken to everyone with a stake in the things that 
osaf.startup replaces over the last few days and gotten their feedback, but 
if I've missed anyone or anything that should be taken into account, please 
let me know.  Thanks.