Use of distro packages

See https://github.com/AbiWord/enchant/pull/61 for a discussion over
whether to use distro packages of autoconf-archive as a build dependency.

My understanding is that it's preferred to put the m4 macros from
autoconf-archive in source control, but I do not find any guidance on this
in the documentation.

Please could we have official guidance on this?

(gnulib, a similar project, recommends use direct from git.)

-- 
http://rrt.sc3d.org