Project restructuring (fixes macOS builds) (#198)

- Create `Include/` folder for all main projects
- Fix some issues here and there (found while moving things)
- All includes are now in `Tactility/` subfolder and must be included with that prefix. This fixes issues with clashing POSIX headers (e.g. `<semaphore.h>` versus Tactility's `Semaphore.h`)

TactilityC/Include/tt_app_alertdialog.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "tt_bundle.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+/**
+ * Show a dialog with the provided title, message and 0, 1 or more buttons.
+ * @param[in] title the title to show in the toolbar
+ * @param[in] message the message to display
+ * @param[in] buttonLabels the buttons to show, or null when there are none to show
+ * @param[in] buttonLabelCount the amount of buttons (0 or more)
+ */
+void tt_app_alertdialog_start(const char* title, const char* message, const char* buttonLabels[], uint32_t buttonLabelCount);
+
+/**
+ * @return the index of the button that was clicked (the index in the array when start() was called)
+ */
+int32_t tt_app_alertdialog_get_result_index(BundleHandle handle);
+
+#ifdef __cplusplus
+}
+#endif