Fix 64-bit VS2013 build

Do not pull in libethereum/Client.h into QT.
This is not necessary the most sane thing to do, but without it I cannot avoid getting 
C:/Program Files (x86)/Windows Kits/8.1/Include/um/winsock2.h(949): error : Can't concatenate non identifier tokens
erros.
Use sha3(header) rather than sha3(block) for hash.
Target block time of 4s.
Version bumps.
Fix libethereumx build issues.
Fix undefined symbols.
Link ethereum.
Move to capabilities-based networking.
Merge branch 'develop' into basenet
Partially rewired network.
Network work ongoing.
Add caktux's JS console helpers.
Merge pull request #294 from SharpCoiner/patch-2

Fix 64-bit VS2013 build
Slowing bashing code into shape.
New net is compiling.
Allow local networking option.
Minor fix.
Fixed #299.
Merge branch 'basenet' into develop
Merge branch 'develop' of github.com:ethereum/cpp-ethereum into develop