Add float constant token
Add error constants and remove TK_UNMATCHED
Return ERR_UNMATCHED on unmatched token
Ignore comments
Check integer and hex values. error: ERR_VAL
Handle floats and check its value. error: ERR_VAL
Fix float definition
Define all valid missing tokens constants

[,],{,},(,),;,!,-,+,*,/,=,<,>
==,>=,<=,&&,||