* tests/scripts/*: Switch TAB chars to #TAB# markup

* tests/scripts/*: Switch TAB chars to #TAB# markup

Avoid Emacs local variable settings to disable whitespace cleanup,
by creating markup tokens for TAB characters (#TAB#) and space
characters (#SPACE#) (for end-of-line spaces).  Modify all the
tests that use TABs to use the new markup.  This requires changing
some old-fashioned tests to use the modern run_make_test().  Also
remove some of the comments regarding test numbers now that the
framework keeps track.