A few small changes

[laurenthuberdeau]

Context

I wanted to see which part of the compilation process took the longest and made a few useful changes:

1. Use do_while in get_tok: this saves 1 temporary and should make it faster and the cost shorter
2. Remove duplicated print_string_char function only used by the debug.c module (otherwise dead code)
3. Add a script to make it easy to invoke the reader/tokenizer/parser.
4. Indent the tokenizer output to make it easier to read.