The patch adds test-lib.el file for Emacs tests auxiliary stuff.
Currently, it implements two functions: `visible-buffer-string'
and `visible-buffer-substring'. These are similar to standard
counterparts without "visible-" prefix but exclude invisible
text. The functions are not used anywhere at the moment but
should be useful for testing hiding/showing in the Emacs
interface.
Edited-by: Carl Worth <cworth@cworth.org> Fixed "basic" test to ignore
new test-lib.el file.
