Added new default error code, provisionally named 'default'.
Renamed error code from C++ keyword.
Moved Clock from maidsafe::common to maidsafe namespace
Merge pull request #54 from breese/next

Moved Clock from maidsafe::common to maidsafe namespace
Merge pull request #44 from BSMaidSafe/MAID-307_default_error_code

Added new default error code, provisionally named 'default'.