1.0.21.26: bullet-proof (?) use of LOAD-SHARED-OBJECT in tests

1.0.21.26: bullet-proof (?) use of LOAD-SHARED-OBJECT in tests

 * Previously LOAD-SHARED-OBJECT looked for the shared object first
   in the current directory, and if it existed there, it passed the
   absolute pathname to dlopen().

   New version passes the native namestring of the designated pathname,
   absolute or relative -- which leads to dlopen() on some platforms not
   looking in the current directory unless "." is in LD_LIBRARY_PATH.

   So add TRUENAME calls to the test-suite when the .so lives there.

 * Mention the change of semantics in NEWS.

 * Delete trailing whitespace.