build: update distcheck build flags

"make dist" creates a .tar of the source.
"make distcheck" does a complete build on that .tar
Make sure we have an up-to-date list of configure options.

Makefile.am

@@ -6,9 +6,10 @@ AUTOMAKE_OPTIONS = 1.6 foreign
 EXTRA_PROGRAMS = mutt_dotlock pgpring pgpewrap mutt_md5
 
 # Test the .tar file by building everything
-AM_DISTCHECK_CONFIGURE_FLAGS = --enable-debug --enable-gpgme --enable-notmuch \
-	--with-bdb --with-gdbm --with-gnutls --with-gss --with-kyotocabinet \
-	--with-lmdb --with-qdbm --with-sasl --with-tokyocabinet
+AM_DISTCHECK_CONFIGURE_FLAGS = --enable-debug --enable-flock --enable-gpgme \
+	--enable-mailtool --enable-nfs-fix --enable-notmuch --with-bdb \
+	--with-gdbm --with-gnutls --with-gss --with-kyotocabinet --with-lmdb \
+	--with-mixmaster --with-qdbm --with-sasl --with-tokyocabinet
 
 SUBDIRS = m4 contrib imap