GUI: support for octave arguments and integrate with run-octave. * src/octave.h (octave_initialize_interpreter, octave_execute_interpreter): New functions. (octave_cmdline_argc, octave_cmdline_argv, octave_embedded): New variables. * src/octave.cc (octave_cmdline_argc, octave_cmdline_argv, octave_embedded): New variables. (octave_initialize_interpreter, octave_execute_interpreter): New functions. (octave_main): Rewrite using them. * run-octave.in (octave_executable): New variable. (-gui): New option flag. * gui/src/octave-adapter/octave-main-thread.cc (octave_main_thread::run): Use octave_execute_interpreter. * gui/src/octave-gui.cc (dissociate_terminal): New function. (main): Use it. Also use octave_initialize_interpreter.

--- a/src/octave.h
+++ b/src/octave.h
@@ -29,6 +29,15 @@
 
 extern OCTINTERP_API int octave_main (int argc, char **argv, int embedded);
 
+extern OCTINTERP_API void
+octave_initialize_interpreter (int argc, char **argv, int embedded);
+
+extern OCTINTERP_API int octave_execute_interpreter (void);
+
+extern OCTINTERP_API int octave_cmdline_argc;
+extern OCTINTERP_API char **octave_cmdline_argv;
+extern OCTINTERP_API int octave_embedded;
+
 #ifdef  __cplusplus
 }
 #endif