GUI initialization extracted from PrusaSlicer.cpp to GUI_Init.cpp/hpp.

Implemented try/catch blocks for Slic3r exceptions and std::exceptions
with GUI error reporting. This is extremely important to report
corruption of PrusaSlicer.ini.

src/slic3r/GUI/GUI_Init.hpp

@@ -0,0 +1,24 @@
+#ifndef slic3r_GUI_Init_hpp_
+#define slic3r_GUI_Init_hpp_
+
+namespace Slic3r {
+namespace GUI {
+
+struct GUI_InitParams
+{
+	int		                    argc;
+	char	                  **argv;
+
+    std::vector<std::string>    load_configs;
+    DynamicPrintConfig          extra_config;
+    std::vector<std::string>    input_files;
+
+	bool	                    start_as_gcodeviewer;
+};
+
+int GUI_Run(GUI_InitParams &params);
+
+} // namespace GUI
+} // namespace Slic3r
+
+#endif slic3r_GUI_Init_hpp_