Save recording status to file to reload it when gsr overlay restarts

include/Process.hpp

@@ -14,5 +14,6 @@ namespace gsr {
     bool exec_program_daemonized(const char **args);
     // Arguments ending with NULL
     pid_t exec_program(const char **args);
-    bool is_gpu_screen_recorder_running(pid_t &gsr_pid, GsrMode &mode);
+    // |output_buffer| should be at least PATH_MAX in size
+    bool read_cmdline_arg0(const char *filepath, char *output_buffer);
 }