Support for PC platform (#12)

* improvements for cross-platform compiling

* moved tactility-core to libs/

* splitup improvements

* remove git/gitmodules from freertos

* better platformbetter platform checks

* added build scripts

* delete mbedtls

* re-add mbedtls

* fixes and improvements

* added pc build

* simplify build scripts

* revert build scrpit

* updated builds

* fix for pc

* fix for pc

* fix for build

app-sim/src/main.c

@@ -0,0 +1,42 @@
+#include "log.h"
+
+#include "FreeRTOS.h"
+#include "task.h"
+#include "portmacro.h"
+
+
+void vAssertCalled( unsigned long ulLine, const char * const pcFileName )
+{
+    static portBASE_TYPE xPrinted = pdFALSE;
+    volatile uint32_t ulSetToNonZeroInDebuggerToContinue = 0;
+
+    /* Parameters are not used. */
+    ( void ) ulLine;
+    ( void ) pcFileName;
+
+    taskENTER_CRITICAL();
+    {
+        /* You can step out of this function to debug the assertion by using
+        the debugger to set ulSetToNonZeroInDebuggerToContinue to a non-zero
+        value. */
+        while( ulSetToNonZeroInDebuggerToContinue == 0 )
+        {
+        }
+    }
+    taskEXIT_CRITICAL();
+}
+
+int main() {
+//    static const Config config = {
+//        .hardware = NULL,
+//        .apps = {
+//            &hello_world_app
+//        },
+//        .services = { },
+//        .auto_start_app_id = NULL
+//    };
+//
+//    tactility_start(&config);
+    TT_LOG_I("app", "Hello, world!");
+    return 0;
+}