Remove requirement of ending a namespace with semicolon.

  Now if a semicollon is added, will be treated as an empty statement.
Remove wrong sdl.timer_t field
Add several new SDL builtins, bug fixes and some redesign.

    Redesign:
o now instead of exporting an uint32_t window or device id it directly
  pass the window_t pointer in the event_t window field (devices are
  still a todo).
o created several change_record builtins for missing "get" and "set"
  functions, that now have an exported field and a hidden field
  (cannot be reached with the language because it uses an internal
  invalid name), and when calling the change_record function, if the
  exported field was changed, it will try to do the appropriate action
  to call the proper "set" function; the "get" function is not required
  because the field already has the "get" value.
o some internal hash tables were added for the mapping of ids and
  SDL to language type specific pointers.

  Bug fixes:
o returning uint32_t requires special handling on 32 bit because the
  language only supports signed word integers or mpz_t in the vm
  registers, so, if needing to return an uint32_t with the topmost
  bit set, must change the return type to t_mpz.

  New builtins:
o change_window (language specific)
o get_window_renderer (SDL_GetRenderer)
o change_renderer
o get_renderer_window (language specific)
o create_texture (SDL_CreateTexture)
o create_texture_from_surface (SDL_CreateTextureFromSurface)
o change_texture (language specific)