FormatPrinter has unhandled cases

[DeanoBurrito]

FormatPrinter (the class that handles printf style formatting) current outputs 'TOKEN' in place of all tokens. We should replace this so its actually functional.
This can be done in stages:

• Integers (signed and unsigned)
• Floating point numbers (single, double and extended precision)
• Misc specifiers (string, single char, output char count)
• Custom specifiers (bool).

[DeanoBurrito]

Late update: most functionality is implemented, floating point numbers are the only type missing.
Precision and width have various levels of support depending on type, these could use more work.