[cairo] cairo Summer-of-code participant introduction

[Bill Spitzak]

Kai-Uwe Behrmann wrote:
> Indeed, for moving around computers I much refered to C. Until C++ 
> ABI stability is otherwise proofed. Otherwise the OpenEXR implementation 
> would be fine.
> 
> I dont know if dependencies or parts of Cairo are allowed to be other 
> languages than C.
> 
> 
> kind regards
> Kai-Uwe Behrmann

Actually what I thought could be done is to extract the algorithms from 
the C++ code and make a "C half" library. The main things to get are the 
casts to/from float which would be C functions, and the constants like 
the limits. Most of the rest is operator overloading which can be 
ignored (almost all the math seems to work by converting to float, doing 
the function, then converting back).