Fix to accommodate upgrade of Boost to version 1.57.0.
Merge remote-tracking branch 'origin/next' into MAID-432_boost_1_57
Merge pull request #20 from Fraser999/MAID-432_boost_1_57

Fix to accommodate upgrade of Boost to version 1.57.0.
Temporarily set default error in ReturnCode constructor to CommonErrors::success.
Merge pull request #30 from BSMaidSafe/next

Temporarily set default error in ReturnCode constructor to CommonErrors:...