added:

* win32_slim.h: includes the minimal version of windows.h
modified:
 * cthread: added lock_t c++ class
 * os: added getUserName()
 * socket: modified socket_len_t to sk_len_t to better follow naming convetions in file
 * str: added operator std::string() to str_t

os.h

@@ -6,21 +6,26 @@ extern "C" {
 
 #include <stddef.h>
 #include <string.h>
+#include "str.h"
 
 #ifdef _WIN32
     #include <stdio.h>
-    #include <BaseTsd.h> // SSIZE_T
+    #include "win32_slim.h"
     typedef SSIZE_T ssize_t;
     ssize_t getdelim(char **buf, size_t *bufsz, int delimiter, FILE *fp);
     ssize_t getline(char **line_ptr, size_t *n, FILE *stream);
     #define stricmp _stricmp
 #else
     #define stricmp strcasecmp
-    #define _GNU_SOURCE
+    #ifndef _GNU_SOURCE
+        #define _GNU_SOURCE
+    #endif
     #include <stdio.h>
     #include <sys/types.h> // ssize_t
 #endif
 
+str_t getUserName();
+
 #ifdef __cplusplus
 } // extern "C"
 #endif