Include a gas limit for web3 constant calls

Provide formal verification input.

Self contained Travis build - work without Internet connection

remix integration

Minor corrections

Fix dargbar width

Create a self contained ZIP with each travis build

Use solc.js compiler [WIP]

On Firefox the element with "dragbar" ID covers 90% of the element with "input" ID scroll bar. So it is really hard to drag the scroll bar.
I recommend to change in the #dragbar CSS element the Width from 1em to 0.5em.

Missed this in #124

Fix gas limit & out-of-gas conditions in VM mode

Finally, browser-solidity won't assume that an out-of-gas transaction was successful.

Support changing the gas limit in the UI