[nem-en] Formatting strings in printf-style functions

[Kamil Skalski]

Current support for formatting strings in Nemerle.IO.f/s//printf  functions 
isn't rich (just basic types without precisions specifiers), but there is one 
issue, which probably should be changed.

printf ("%f", 5.5)   <---   parameter is expected to be of type double

in original libc functions it is a float type, while double is specified by
%lf

Now we have to decide if we want %f == double, which is default floating point 
type in Nemerle and %lf == decimal (and no specifier for float) or change
specification to something more C-conformant (could break some code).

I opt for latter.

-- 
Kamil Skalski
http://nemerle.org developer