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
Merge pull request #34 from dschatzberg/patch-1

Fix md5.c++ to work on non x86 systems
fix output of Int8 values for Solaris
make capnp-test.sh compatible with Solaris sh(1), test(1) and cmp(1)
Solaris doesn't have backtrace()
sched_yield() is in librt on Solaris
Merge pull request #33 from dmitri-shubin/master

Solaris compatibility
Initial implementation of promises.
Reduce generated code for Promises by making most of the node implementations mostly non-templated.
Merge branch 'master' of https://github.com/kentonv/capnproto
Update Makefile.am.
Port SimpleEventLoop to pthreads for non-Linux platforms.
Revert -Wl,--no-undefined change since it doesn't work on Mac (among other platforms).
Update test config.
Events queued together should occur in logical order.
__linux__ -> KJ_USE_FUTEX
I guess this is supposed to be single-dash but it works either way?
I{REQUIRE,ASSERT} -> {REQUIRE,ASSERT} since these aren't inline anymore.
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.
Fix location of empty union error.