Add the first real working script

[Kjarrigan]

RocketLang is done (as far as the book is concerned) and I tried to solve a real problem with it. It was quite a journey to get it (sort) of working due to a lot of missing stuff (some crucial, some convenience). So I want to share this piece of code to get a better feeling what is currently missing, what is possible and what not.

The issues I had (sorted from unbelievable to cumbersome):

1. no string[idx] -> I had to convert the input string into an array[]
2. no string comparison ("(" == "(" is currently false) -> a Hash/Dictionary worked
   • was fixed in 0.9.6-rc2
3. no loops -> recursion worked
4. no exit or raise
5. running the script always outputs null at the end
6. no comments -> strings everywhere
7. the variable scope is sometimes a bit weird, I had to use more let than I felt was necessary

$ rocket-lang examples/aoc2015_day1.rl
Solution Day 1 Part 1: 
127
null