Merge branch 'develop' into btsx

Conflicts:
	libraries/blockchain/chain_database.cpp
	libraries/blockchain/include/bts/blockchain/config.hpp
	libraries/blockchain/market_engine.cpp
	libraries/client/include/bts/client/client.hpp
	programs/qt_wallet
	programs/web_wallet
Fix fork
Merge pull request #39 from vikramrajkumar/btsx

merge latest
Bump version
Correctly emulate pre-fork-4 behavior to allow us to safely validate old blocks without asserting or accessing uninitialized memory.  Fixes some crashes reported, like one reported in BitShares/bitshares_toolkit#647
Remove btsx specific fork changes
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop

Conflicts:
	libraries/blockchain/market_engine.cpp
Merge branch 'develop' into btsx

Conflicts:
	libraries/blockchain/market_engine.cpp
	libraries/blockchain/market_operations.cpp
Add wallet API calls for creating and opening mail

The wallet can now create an email to a recipient, and as that
recipient, open said mail.
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
Merge pull request #40 from vikramrajkumar/btsx

merge latest
Restore missing change from downstream
Update submodules
Merge pull request #41 from vikramrajkumar/btsx

Update submodules
match upstream
Merge pull request #43 from vikramrajkumar/btsx

match upstream
rename file
add checkpoint
Merge remote-tracking branch 'remotes/origin/master' into emfrias_master

Conflicts:
	libraries/blockchain/market_engine.cpp
Merge pull request #44 from vikramrajkumar/btsx

checkpoint