- make account names, permissions, and message types fixed strings
- move sys_contract implementation to separate cpp file
- disable deprecated warnings on OS X
- define authority class

- absent signature verification

Only one call, but that call works!

Replace the C-style typless macros in config.hpp with C++-style const
definitions.

All tests now pass again. :)

Test of the recent slots filled are now working correctly.

Yeah, P2P works now, as far as I can tell. Nodes connect, sync, and stay
in sync. Not rigorously tested yet, but the basics are there.

Dunno what happened, but I don't have time to fix it right now.

Fix the stuff that broke in merge.

Define a new p2p_plugin as the adaptor between appbase and the old P2P
library, and wire things together. This is mostly working, but for some
reason peers won't stay connected to sync, but instead just drop their
connection (with a TCP reset, no less) right before syncing, without
bothering to log about why. I suspect the failure is at a lower level. :
(

Remove the new types library temporarily, until the missing sources are
checked in, so that builds work again.

The producer plugin (now called producer_plugin) is now adapted to the
new appbase system, and appears to be working correctly.

Also, eliminate some boilerplate around OBJECT_CTOR macro! Now you can
OBJECT_CTOR(objname, (field1)(field2)) to indicate that field1 and field2
are dynamically allocated objects and need to be initialized with the
allocator.

Bring in chain_plugin, net_plugin, http_plugin; wire appbase and plugins
into existing infrastructure, remove old app infrastructure.

As discussed on #5, use hashes as the generated_transaction_id_type
instead of serial numbers.

Define structures around cycles/threads, etc.

Also implement merkle digests. :)