v1.2.0

• Fixed comparison between nil and simple types (int, bool, string).
• Fixed equal operation on different nil types.
• Fixed bug with nil vars, now is possible to compare fields with nil literal.
• Fixed default type of map created in expr.
• Fixed type checker for interface's methods.
• Added bytecode virtual machine.
• Added optimizing compiler.
• Added builtin functions: all, none, any, one, filter, map.
• Added operator overloading.
• Improved error messages.