* `minetest.string_to_pos(string)`: returns a position or `nil`
* Same but in reverse.
* If the string can't be parsed to a position, nothing is returned.
-* `minetest.string_to_area("(X1, Y1, Z1) (X2, Y2, Z2)")`: returns two positions
+* `minetest.string_to_area("(X1, Y1, Z1) (X2, Y2, Z2)", relative_to)`:
+ * returns two positions
* Converts a string representing an area box into two positions
+ * X1, Y1, ... Z2 are coordinates
+ * `relative_to`: Optional. If set to a position, each coordinate
+ can use the tilde notation for relative positions
+ * Tilde notation: "~": Relative coordinate
+ "~<number>": Relative coordinate plus <number>
+ * Example: `minetest.string_to_area("(1,2,3) (~5,~-5,~)", {x=10,y=10,z=10})`
+ returns `{x=1,y=2,z=3}, {x=15,y=5,z=10}`
* `minetest.formspec_escape(string)`: returns a string
* escapes the characters "[", "]", "\", "," and ";", which can not be used
in formspecs.