cursor: break line after \n

Up to now, the cursor broke the line *before* the
\n and made that character the 0th one in the new
line.  I don't know why i did this, but at least
it's fixed now.

src/lex/cursor.rs

@@ -18,7 +18,7 @@ impl Iterator for Cursor {
             let c = self.raw[self.pos];
             self.pos += 1;
 
-            if c == '\n' {
+            if self.current == Some('\n') {
                 self.new_line();
             } else {
                 self.col += 1;
@@ -51,10 +51,9 @@ impl Cursor {
             self.pos -= 1;
             let c = self.raw[self.pos];
 
+            self.col -= 1;
             if self.col == 0 {
                 self.prev_line();
-            } else {
-                self.col -= 1;
             }
 
             self.current = Some(c);
@@ -132,7 +131,7 @@ impl Cursor {
 
     fn new_line(&mut self) {
         self.line_lengths.push(self.col);
-        self.col = 0;
+        self.col = 1;
         self.line += 1;
     }