Merge pull request #18 from vikramrajkumar/btsx

Merge upstream
Merge pull request #19 from vikramrajkumar/btsx

Merge upstream
Delete ClientWrapper before shutdown, which allows all of the async tasks in bts::client, bts::net, etc. to shutdown cleanly (fixes crashes & asserts at shutdown)
Updates to shutdown procedure. It still doesn't work right, but it's better.
Detonate implosion grenade as soon as client is destroyed.

Screw you, sleeping threads! I keel you! Hahahahaaaa!
Fix spurious crash detection
Revert exit call and cleanup shutdown of bitshares client so that GUI shuts down properly.
Avoid capturing a smart pointer to the wallet in a lambda owned by the wallet, which was preventing it from being garbage collected.
Remove some old fc logfile managing code inherited from keyhotee and no longer useful.
Merge branch 'develop' into btsx