Fix indentation of quad.c and tds.c

Because use TABS and not spaces. And don't leave tabs on empty lines.
NO TABS ON AN EMPTY LINE!

Signed-off-by: Celelibi <celelibi@gmail.com>
Add comment support to the lexer

That makes testing easier.

Signed-off-by: Celelibi <celelibi@gmail.com>
Adding a function to return the last quad

Quads are stored in a list in the wrong order for the grammar to use it.
Therefor, operations need to go get the last quad instead of the first.

Signed-off-by: Celelibi <celelibi@gmail.com>
Expression construction now use the right quad

The right quad is the last one. Not the first one.

Signed-off-by: Celelibi <celelibi@gmail.com>