There's no need to keep autogenerated files in
repository. Those dockapps which use autotoold must be
autoreconf'ed prior to build, those which use imake must be
xmkmf'ed. As of wmbiff, AC_PATH_XTRA_CORRECTED was a hack to
avoid bug in older autoconf version, which is no longer needed
(it's 2012 now already).
Signed-off-by: Alexey I. Froloff <raorn@raorn.name>