add initial RTOS support

now without io devices and console

git-svn-id: svn://db.shs.com.ru/pip@683 12ceb7fc-bf1f-11e4-8940-5bc7170c53b5

src_main/piplatform.h

@@ -45,13 +45,18 @@
 #    define ANDROID
 #  endif
 #endif
+#ifdef PIP_FREERTOS
+#  define FREERTOS
+#endif
 #ifndef WINDOWS
 #  ifndef QNX
 #    ifndef FREE_BSD
 #      ifndef MAC_OS
 #        ifndef ANDROID
 #          ifndef BLACKBERRY
-#            define LINUX
+#            ifndef FREERTOS
+#              define LINUX
+#            endif
 #          endif
 #        endif
 #      endif