Get rid of no-longer-needed object-specific methods of DynamicStruct.  Use get().as<ObjectPointer>() instead.

Revamp generated interface to Object fields.  Now there is an ObjectPointer::{Reader,Builder}.  This will simplify the dynamic API (next change) and also makes it easier to delegate decisions about the object type to a function that doesn't know about the context where the object lives (i.e. by passing an ObjectPointer::Builder).

Factor Pointer{Reader,Builder} out from {Struct,List}{Reader,Builder}.  Will make it easier to deal with Object fields.

Let's go ahead and rename  to , acknowledging that this may expand to support pipeline operations that are not simply fetching members.

Improve and simplify event ordering.  When explicitly calling an EventLoop, events are now always added to the end of the queue, ensuring deterministic run order and making yield() obsolete.  OTOH, then() may queue events to run immediately, preempting other events.

Solaris compatibility

Fix md5.c++ to work on non x86 systems

ctx is not a pointer but was being used with the arrow operator on non-x86 systems

Fix LDFLAGS and work around a Fedora bug that broke pthread linking

The Fedora bug caused the DT_NEEDED for libpthread to be omitted, and
the missing -Wl before no-undefined prevented binutils from detecting it.

-export-dynamic is unnecessary for libraries, so this removes it, too.