Python wrapper increased optional parameters

Added options for tolerance variables and max iterations to the python wrapper for ecos offering the same functionality as MATLAB.  I followed the SCS template where possible, so everything is handled almost exactly the same, except that I left verbose as its own argument to preserve backwards compatibility.  I also followed the SCS model of providing limited information about the arguments in the readme.

I opted to statically allocate the settings array.  this creates slightly more overhead (several floats) in the scenario where there are no opt arguments, but avoids needing to worry about memory allocation.  If we're worried about the couple floats, we can switch to dynamic allocation.