handling substraction
handling of tests by Makefile improved
Missing \n in a print function
changed run_tests in order to make it indent properly even with the TESTS=*.test
run_tests improved in order to print filename before starting the test
changes in order to make hello_world function again
improved handling of string, now it's still needed to work on built_ins declaration
Now handling properly built_ins declaration, hello world working
Some test files added and now substraction, division, multiplication and parenthesis handling should work