deprecated os.h and removed scanf from istream as it can't return the end position

deprecated/os.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stddef.h>
+#include <string.h>
+#include "str.h"
+#include "collatypes.h"
+
+#ifdef _WIN32
+    #include <stdio.h>
+    #include "win32_slim.h"
+    isize getdelim(char **buf, size_t *bufsz, int delimiter, FILE *fp);
+    isize getline(char **line_ptr, size_t *n, FILE *stream);
+    #define stricmp _stricmp
+#else
+    #ifndef _GNU_SOURCE
+        #define _GNU_SOURCE
+    #endif
+    #include <stdio.h>
+    int stricmp(const char *a, const char *b);
+#endif
+
+str_t getUserName();
+
+#ifdef __cplusplus
+} // extern "C"
+#endif