merge rust-rendering-2 to master

restructuring

subscript assignment parsing

anonymous functions

functions act like variables

name resolution and features

ternary operators

increment and decrement, desugaring

switch to keywords

convert lexer to use utf-8 character, bitwise operations

for

array, subscript

return, break, continue

functions added

while and loop statements

if statement

call, member access, declaration, and assignment

logical or and logical and

equality, comparison, unary added

calculator parser kabel