Integrate 0.5.10 error recovering feature

[flantony]

In solc release 0.5.10, Steve C. Johnson-style error recovery was added experimentally. To use it, from solc use option --error-recovery.

From JavaScript and solcjs use:

const input = { language: 'Solidity', settings: { parserErrorRecovery: true, ... } }

[flantony]

PR #263