Fix public issue #7: Don't use internal variables named ac_*, as those belong to autoconf's namespace. R=csilvers DELTA=6 (0 added, 0 deleted, 6 changed) Revision created by MOE tool push_codebase. MOE_MIGRATION=988 git-svn-id: http://snappy.googlecode.com/svn/trunk@6 03e5f5b5-db94-4691-08a0-1a8bf15f6143