Allow %s as generic format specifier in printf (#453)

* Allow %s as generic format specifier in printf

Signed integers are formatted as %d
Unsigned integers are formatted as %u
Doubles are formatted as %f
Chars are formatted as %c
Void Pointers are formatted as %p

* Remove '%S' handling and use visitor for generic format strings

* Default for floating point is now "%g" rather than "%f"
2 files changed