This includes removing AC_CANONICAL_BUILD/AC_CANONICAL_TARGET (weren't
used), renaming configure.in to configure.ac (required for automake
1.13 coming up), moving automake options to configure.ac (removes use
of AM_INIT_AUTOMAKE with two parameters, which is also gone with
automake 1.13).
Also remove empty files and declare the system foreign, not gnu (NEWS
and AUTHORS are not used), avoid re-declaring in the distributed files
the conditional sources (automake takes care of that), and don't use
-Werror (as it would fail to build with GCC 4.6 and 4.7).
Signed-off-by: Diego Elio Pettenò <flameeyes@flameeyes.eu>