fix enable-sasl-pwdb

* using --enable-sasl-pwdb will make the compile fail with:

sasl_defs.c:148:4: error: initialization from incompatible pointer type [-Werror]
This adds the "shutdown" command to the server. This allows for better
automation (at least,... I find that it makes for better automation).
Merge pull request #22 from gabriel-samfira/master

Compile fails using enable-sasl-pwdb
Merge pull request #26 from trondn/brians-shutdown

This adds the "shutdown" command to the server. This allows for better
Fix make maintainer-clean
add aclocal 1.12 in autogen.sh
Merge remote-tracking branch 'upstream/master'