Added substring-based account selection to sip_register

Ignore-this: c9d7b014f55fd603a69921b2d44f86f1

darcs-hash:20090521072001-1e3d8-ad14dedb2b25e0fde15b295fa3ad2d47b00be2e6
Added substring-based account selection to sip_auto_publish_presence

Ignore-this: 709af34cafd8158e986e6ef24a84527e

darcs-hash:20090521072502-1e3d8-bdd89da3156ae002d5f0aeb7e84ab3cfe9d43be0