autogen.sh fails with automake-1.12

[gustafj]

Error from automake:

/usr/share/automake-1.12/am/ltlibrary.am: warning: 'umfuseext2.la': linking libtool libraries using a non-POSIX
/usr/share/automake-1.12/am/ltlibrary.am: archiver requires 'AM_PROG_AR' in 'configure.ac'

The ugly fix is to remove -Werror from:
AM_INIT_AUTOMAKE([-Wall -Werror foreign])
In configure.ac

See: http://code.google.com/p/snappy/issues/detail?id=67 for more info on same problem.