More robust cleanup handling

rktwebview.cpp

@@ -35,6 +35,7 @@
 
 #ifdef _WIN32
 #define strdup _strdup
+#define sleep_ms(ms)  Sleep(static_cast<DWORD>(ms))
 #endif
 
 //#define DEBUG
@@ -833,3 +834,10 @@ rkt_data_t *rkt_webview_info()
 }
 
 
+
+void rkt_webview_exit_done(int done)
+{
+    if (!done) {
+        ERROR0("rkt_webview_exit_done called with 'false', i.e. this library did not have a cleanup call\n");
+    }
+}

rktwebview.h

@@ -13,6 +13,7 @@ extern "C" {
 RKTWEBVIEW_EXPORT void rkt_webview_env(const char *env_cmds[]);
 RKTWEBVIEW_EXPORT void rkt_webview_init(const char *from);
 RKTWEBVIEW_EXPORT void rkt_webview_cleanup();
+RKTWEBVIEW_EXPORT void rkt_webview_exit_done(int done);
 RKTWEBVIEW_EXPORT void rkt_webview_register_evt_callback(void (*f)(int));
 
 RKTWEBVIEW_EXPORT void rkt_webview_set_loglevel(rkt_webview_loglevel_t l);