Applications: unified entry point naming scheme, drop dead code, cleanup. (#628)

applications/accessor/accessor.cpp

@@ -1,7 +1,7 @@
 #include "accessor-app.h"
 
 // app enter function
-extern "C" int32_t app_accessor(void* p) {
+extern "C" int32_t accessor_app(void* p) {
     AccessorApp* app = new AccessorApp();
     app->run();
     delete app;