fixing an issue with destroying empty list in some cases (from 10/36 tests compiling to 34/36)
Some fixes about for variable type, now 35/36 tests working
fixing some invalid reads, now at 3432/3459 free/malloc
Fixing memory leaks, from 3432/3459 to 3438/3459
Fixing memory leaks, from 3438/3459 to 3444/3459
Fixing memory leaks, from 3444/3459 to 3448/3461
Fixing memory leaks, from 3448/3461 to 3454/3461
Fixing memory leaks, from 3454/3461 to 3458/3461 (for tests/test_appel.rubic) the 3 remaining are due to lex
Fixing memory leaks due to parser, adding yylex_destroy() after yyparse()