Changed prefix from b_ to br_
Added "br_create_menu(int,int,int,int)"
Added structure/typedef "BITMAP"
Added "br_create_bitmap(const char*)"
Added "br_add_menu_item(const char*,BITMAP*)"
Made "br_main()" more runnable as a thread
~ added tvars_o to contain thread variables.
Implemented "br_create_bitmap" and "br_add_menu_item"