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

libs/mbedtls/tests/suites/test_suite_error.function

@@ -0,0 +1,21 @@
+/* BEGIN_HEADER */
+#include "mbedtls/error.h"
+/* END_HEADER */
+
+/* BEGIN_DEPENDENCIES
+ * depends_on:MBEDTLS_ERROR_C
+ * END_DEPENDENCIES
+ */
+
+/* BEGIN_CASE */
+void error_strerror(int code, char *result_str)
+{
+    char buf[500];
+
+    memset(buf, 0, sizeof(buf));
+
+    mbedtls_strerror(code, buf, 500);
+
+    TEST_ASSERT(strcmp(buf, result_str) == 0);
+}
+/* END_CASE */