Use random functions source files on Windows.

Use srand/rand instead of srandom/random (from MichaƂ Janiszewski)

Closes #156.
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index d5bf580..83fd054 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -169,9 +169,13 @@
     zip_source_win32w.c
   )
   IF(CMAKE_SYSTEM_NAME MATCHES WindowsPhone OR CMAKE_SYSTEM_NAME MATCHES WindowsStore)
+    SET(LIBZIP_OPSYS_FILES "${LIBZIP_OPSYS_FILES}"
+      zip_random_uwp.c
+    )
   ELSE()
     SET(LIBZIP_OPSYS_FILES "${LIBZIP_OPSYS_FILES}"
       zip_source_win32a.c
+      zip_random_win32.c
     )
   ENDIF()
 ELSE(WIN32)
diff --git a/lib/zip_random_uwp.c b/lib/zip_random_uwp.c
index ce7d6b8..cec7ec6 100644
--- a/lib/zip_random_uwp.c
+++ b/lib/zip_random_uwp.c
@@ -68,17 +68,17 @@
 zip_uint32_t
 zip_random_uint32(void) {
     static bool seeded = false;
-    
+
     zip_uint32_t value;
-    
+
     if (zip_secure_random((zip_uint8_t *)&value, sizeof(value))) {
         return value;
     }
-    
+
     if (!seeded) {
-        srandom((unsigned int)time(NULL));
+        srand((unsigned int)time(NULL));
     }
-    
-    return (zip_uint32_t)random();
+
+    return (zip_uint32_t)rand();
 }
 #endif
diff --git a/lib/zip_random_win32.c b/lib/zip_random_win32.c
index 16d0f64..052bd4f 100644
--- a/lib/zip_random_win32.c
+++ b/lib/zip_random_win32.c
@@ -64,17 +64,17 @@
 zip_uint32_t
 zip_random_uint32(void) {
     static bool seeded = false;
-    
+
     zip_uint32_t value;
-    
+
     if (zip_secure_random((zip_uint8_t *)&value, sizeof(value))) {
         return value;
     }
-    
+
     if (!seeded) {
-        srandom((unsigned int)time(NULL));
+        srand((unsigned int)time(NULL));
     }
-    
-    return (zip_uint32_t)random();
+
+    return (zip_uint32_t)rand();
 }
 #endif