Marekt: remove mtgox from supported markets

This commit removes mtgox from the supported markets functions (and from ```--market all```) but leaves the underlying code in place.

This also disables the ```goxlag``` function by commenting out that function's code.  This way, if gox comes back later, we can just uncomment that code, and readd gox into the supported markets and such.
Merge pull request #57 from teward/patch-1

Market: remove mtgox from supported markets, remove goxlag command