Floating point support #2

Add floating point support

Lexer support
- Turn 1.3 into a single unit instead of ['1', '.', '3']
Code generation and type checking
- Generate a FloatFetchValue instruction and add to instruction stack
- Push the correct type to the type stack

WIP: 7e49cf1d0a

Fixed lexing bug with . in lexer.d in 806814f01c

We also have LiteralValueFloat now, so this should be done.

Type checking though?

Type checking is done already with:

/**
                * Typechecking
                *
                * If the number literal contains a `.` then it is a float
                * else if is an int (NOTE: This may need to be more specific
                * with literal encoders down the line)
                */
                NumberLiteral numLit = cast(NumberLiteral)statement;
                import std.string : indexOf;
                bool isFloat = indexOf(numLit.getNumber(), ".") > -1; 
                gprintln("NUMBER LIT: isFloat: "~to!(string)(isFloat));
                addType(getType(modulle, isFloat ? "float" : "int"));