Also fixed all conflicting calls of the old functions in the rest of the codebase.
The set of string conversion functions for each float type now consists of those items:
- to_str(), converts to number in base 10
- to_str_hex(), converts to number in base 16
- to_str_radix(), converts to number in given radix
- to_str_exact(), converts to number in base 10 with a exact number of trailing digits
- to_str_digits(), converts to number in base 10 with a maximum number of trailing digits
- implementations for to_str::ToStr and num::ToStrRadix
- from_str(), parses a string as number in base 10 including decimal exponent and special values
- from_str_hex(), parses a string as a number in base 16 including binary exponent and special values
- from_str_radix(), parses a string as a number in a given base excluding any exponent and special values
- implementations for from_str::FromStr and num::FromStrRadix