Minor refactoring, added OP_GETMETHOD

You can use ':' without invoking. So you can grab a method binding to an object and later call it. Also some GC bugs were fixed.

A new preprocessor macro (VM_DEBUG) has been added. Defining this macro will print each instruction thats being executed in the VM, as
well as print each call.

src/cbaselib.c

@@ -4,6 +4,8 @@
 #include "cobj.h"
 #include "cmem.h"
 
+// ================================================================ [BASELIB] ================================================================
+
 int cosmoB_print(CState *state, int nargs, CValue *args) {
     for (int i = 0; i < nargs; i++) {
         CObjString *str = cosmoV_toString(state, args[i]);