Introducing VMFace - common VM interface
Use safe pointers in Executive
Merge branch 'develop' into vm
Revert unnecessary whitespace changes
Merge remote-tracking branch 'origin/vm' into vm
Fix alethzero build
PV49 alterations for creation.
Natspec title and author tag.

- Adding the title and author natspec documentation tags for contracts
- Also using the author tag for functions now
- Tests
Styling issues and add TODO in Interfacehandler
VMFactory - a new way of creating VMs
Merge remote-tracking branch 'upstream/develop' into vm
Merge pull request #586 from LefterisJP/natspec_contract_tags

Natspec title and author tag.
Style fixes (mostly)
Catch exception by reference
Fixing segfault for solc if stdin is given as input file

- Solc should now check its input files and skip them if they don't
  exist or if they are not a valid file
Merge pull request #589 from LefterisJP/solc_stdin_fix

Fixing segfault for solc if stdin is given as input file
fixed solidity not building on macos
user-provided default constructor
removed explicit
Support empty strings.