added the dependency to the project to circumvent crates.io and updated all projects

arduboy-rust/src/library/c.rs

@@ -0,0 +1,11 @@
+//! Clib functions you can use on the Arduboy
+use core::ffi::{c_char, c_size_t};
+
+extern "C" {
+    #[link_name = "strlen"]
+    fn c_strlen(cstr: *const c_char) -> c_size_t;
+}
+/// A C function to get the length of a string
+pub fn strlen(cstr: *const i8) -> usize {
+    unsafe { c_strlen(cstr) }
+}