conditional os in UI xml, add system dialog file open on osx, check api format or error message when opening a document, per-char text wrap on NodeText, additional info on create doc dialog like working path

src/canvas.cpp

@@ -1674,31 +1674,34 @@ void ui::Canvas::project_save_thread(std::string file_path)
     App::I.async_end();
 }
 
-void ui::Canvas::project_open(std::string file_path, std::function<void()> on_complete)
+void ui::Canvas::project_open(std::string file_path, std::function<void(bool)> on_complete)
 {
     std::thread t([=] {
-        project_open_thread(file_path);
+        bool result = project_open_thread(file_path);
         if (on_complete)
-            on_complete();
+            on_complete(result);
     });
     t.detach();
 }
 
-void ui::Canvas::project_open_thread(std::string file_path)
+bool ui::Canvas::project_open_thread(std::string file_path)
 {
     FILE* fp = fopen(file_path.c_str(), "rb");
     if (!fp)
     {
         LOG("cannot write project to %s", file_path.c_str());
-        return; // should probably return a bool
+        return false; // should probably return a bool
     }
 
     PPIHeader ppi_header;
     fread(&ppi_header, sizeof(PPIHeader), 1, fp);
 
     if (!ppi_header.valid())
-        return;
-
+    {
+        LOG("INVALID PPI HEADER");
+        return false;
+    }
+    
     gl_state gl;
     std::shared_ptr<NodeProgressBar> pb;
     if (App::I.layout.m_loaded)
@@ -1832,6 +1835,7 @@ void ui::Canvas::project_open_thread(std::string file_path)
         App::I.title_update();
         App::I.async_end();
     }
+    return true;
 }
 
 ui::Image ui::Canvas::thumbnail_generate(int w, int h)
@@ -2134,7 +2138,6 @@ ui::Layer::Snapshot ui::Layer::snapshot(std::string data_path)
 {
     Snapshot snap;
     static int counter = 0;
-    LOG("errno = %d", errno);
     glBindTexture(GL_TEXTURE_2D, 0);
     //glBindFramebuffer(GL_FRAMEBUFFER, 0);
     for (int i = 0; i < 6; i++)