Continuing terminal I/O

- Made stdio.h work
- Moved printFiletable back into kernel.c
- TODO: Add stdio.h to all files that should use it (probably next commmit)
- Added some more global addresses. There's a memory layout, but i'm not using it
- Got cursor to be drawn
- Calc program now gets user input

src/calc.c

@@ -4,5 +4,8 @@
 __attribute__ ((section("entry")))
 void main() {
     print("Hello, World!\n");
+    char in[32];
+    read(in);
+    print(in);
     return;
 }