Revert "Use builtin variable"
Revert "Use builtin variable"

This reverts commit 0a3d3fcce0fcb07d8ab080d8b1fa9548a2757a9c.

This was done because @bobsummerwill brought up in ethereum/solidity#952
that a longer hash may not be desired.

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