Add -t theme option

`profanity -t bios` loads the bios theme now.

Fix https://github.com/profanity-im/profanity/issues/1286

src/profanity.h

@@ -40,7 +40,7 @@
 #include <pthread.h>
 #include <glib.h>
 
-void prof_run(char *log_level, char *account_name, char *config_file, char *log_file);
+void prof_run(char *log_level, char *account_name, char *config_file, char *log_file, char *theme_name);
 void prof_set_quit(void);
 
 pthread_mutex_t lock;