Raise nice error if an unsupported URL import was attempted
Raise nice error if an unsupported URL import was attempted

ethereum/browser-solidity,Yann-Liang/browser-solidity,serapath-contribution/browser-solidity,Yann-Liang/browser-solidity,soad003/browser-solidity,serapath-contribution/browser-solidity,soad003/browser-solidity,Yann-Liang/browser-solidity,serapath-contribution/browser-solidity,ethereum/browser-solidity,soad003/browser-solidity