[uClibc]here's a new version of strtod

[Manuel Novoa III]

> On a related note, mind doing strtoul and strtol?  I suspect a 
> little macro magic would do the job with your existing code.

I'll take care of it.  Those are a lot easier to handle.

Coincidentally, I was looking at itoa.c, ltoa.c, and ltostr.c.

1) itoa doesn't properly handle INT_MIN.  I fixed it so it works now.
2) ltoa is apparantly not used by anything in uClibc.  Should it be removed?
3) Since these are nonstandard routines, shouldn't they be prefaced by an
underscore?
4) What do you think about having these conversion routines share a common
buffer?