+/**
+ * Resize the two given containers using the given amount of pixels or
+ * percentage points. One of the two needs to be 0. A positive amount means
+ * growing the first container while a negative means shrinking it.
+ * Returns false when the resize would result in one of the two containers
+ * having less than 1 pixel of size.
+ *
+ */
+bool resize_neighboring_cons(Con *first, Con *second, int px, int ppt);