Refactor app launching (#174)

- Refactor the way apps work: Instead of a C interface, they are now C++ classes. The main reasoning is that attaching data to an app was cumbersome. Having different implementations for different kinds of apps was cumbersome too. (3 or 4 layers of manifest nesting for the TactilityC project)
- External apps are still written in C, but they get a createData/destroyData in their manifest, so:
- External apps now have their own manifest.
- All functions in the original AppManifest are removed and replaced by a single `createApp` function
- External apps now automatically register (each app individually!) when they run the first time. As a side-effect they become visible in the `AppList` app!
- Adapted all apps for the new interface.
- Adapted all internal logic for these changes (Gui, ViewPort, Loader, AppContext, AppInstance, etc.)
- Rewrote parts of Loader to use std::shared_ptr to make the code much safer.
- Added a refcount check for the `AppInstance` and `App` at the end of their lifecycle. Show warning if refcount is too high.

Tactility/Source/app/AppInstance.cpp

@@ -25,7 +25,8 @@ State AppInstance::getState() const {
  * Consider not exposing bundle, but expose `app_get_bundle_int(key)` methods with locking in it.
  */
 const AppManifest& AppInstance::getManifest() const {
-    return manifest;
+    tt_assert(manifest != nullptr);
+    return *manifest;
 }
 
 Flags AppInstance::getFlags() const {
@@ -41,19 +42,6 @@ void AppInstance::setFlags(Flags newFlags) {
     mutex.release();
 }
 
-std::shared_ptr<void> _Nullable AppInstance::getData() const {
-    mutex.acquire(TtWaitForever);
-    auto result = data;
-    mutex.release();
-    return result;
-}
-
-void AppInstance::setData(std::shared_ptr<void> newData) {
-    mutex.acquire(TtWaitForever);
-    data = newData;
-    mutex.release();
-}
-
 std::shared_ptr<const Bundle> AppInstance::getParameters() const {
     mutex.acquire(TtWaitForever);
     std::shared_ptr<const Bundle> result = parameters;
@@ -61,29 +49,9 @@ std::shared_ptr<const Bundle> AppInstance::getParameters() const {
     return result;
 }
 
-void AppInstance::setResult(Result result) {
-    std::unique_ptr<ResultHolder> new_holder(new ResultHolder(result));
-    mutex.acquire(TtWaitForever);
-    resultHolder = std::move(new_holder);
-    mutex.release();
-}
-
-void AppInstance::setResult(Result result, std::shared_ptr<const Bundle> bundle) {
-    std::unique_ptr<ResultHolder> new_holder(new ResultHolder(result, std::move(bundle)));
-    mutex.acquire(TtWaitForever);
-    resultHolder = std::move(new_holder);
-    mutex.release();
-}
-
-bool AppInstance::hasResult() const {
-    mutex.acquire(TtWaitForever);
-    bool has_result = resultHolder != nullptr;
-    mutex.release();
-    return has_result;
-}
-
 std::unique_ptr<Paths> AppInstance::getPaths() const {
-    return std::make_unique<AppInstancePaths>(manifest);
+    tt_assert(manifest != nullptr);
+    return std::make_unique<AppInstancePaths>(*manifest);
 }
 
 } // namespace