Fixed all the VS2013 build issues.

- Updated projects after all the re-potting.
- For simplicity, there's just one VS project for all the libethereum projects, however VS doesn't like duplicate source file names within the same project. To get around this I've created some "single compilation units" for some folders, these probably also compile faster than multiple files.
- Some 32bit only compile errors in RLP (cryptic template ambiguity) were resolved by explicitly invoking operator T() rather than doing a cast to T.
- Moved multiple implementations of toString(h256s const& _bs) into FixedHash.h
- Release shutdown deadlock problem is outstanding.