empty files should not be processed, makes no sense imho

update to vendor version 2.72

fix a merge issue

fixes ticket #2

autoconf: Support escaping and quoting in LDFLAGS and similar vars.

This support makes ac_link honor escaping & quoting in variables which
may be used to preserve spaces in options and similar things. See #156
for details.


git-svn-id: http://svn.netlabs.org/repos/ports/autoconf/trunk@2192 8d6eb4b1-0faa-de11-b929-00e081727c95