[ECOS] floating point output

[Robin Farine]

Hi,

When using printf() and friends with special floating point numbers, i.e. x such
as finite(x) returns 0, a buffer overflow occurs. The attached patch adds checks
to the cvt() routine to handle the NaN & Inf cases separately. Is this the
correct thing to do or should the application test for special cases (I do not
have the C99 standard document to verify this).

Robin