Added docs on MySQL queries blocking main thread.

Added to the RST docs to describe how queries to MySQL will block a nova
service.

Change-Id: I4ae209e2827978cc5469162d386197f2e46b342d

.mailmap

@@ -38,6 +38,7 @@
 <josh@jk0.org> <josh.kearney@rackspace.com>
 <justin@fathomdb.com> <justinsb@justinsb-desktop>
 <justin@fathomdb.com> <superstack@superstack.org>
+<lorin@nimbisservices.com> <lorin@isi.edu>
 <masumotok@nttdata.co.jp> Masumoto<masumotok@nttdata.co.jp>
 <masumotok@nttdata.co.jp> <root@openstack2-api>
 <matt.dietz@rackspace.com> <matthewdietz@Matthew-Dietzs-MacBook-Pro.local>

Authors

@@ -112,7 +112,7 @@ Koji Iida <iida.koji@lab.ntt.co.jp>
 Liam Kelleher  <liam.kelleher@hp.com>
 Likitha Shetty <likitha.shetty@citrix.com>
 Loganathan Parthipan <parthipan@hp.com>
-Lorin Hochstein <lorin@isi.edu>
+Lorin Hochstein <lorin@nimbisservices.com>
 Lvov Maxim <usrleon@gmail.com>
 Mandell Degerness <mdegerne@gmail.com>
 Mark McLoughlin <markmc@redhat.com>