Added tests to verify account can be used for presence subscription

Ignore-this: 2a11c581fbd52f2bec4950d5d43a718

darcs-hash:20090331114644-1e3d8-1e34e7246d4d34a5e25be9225a359da81f09f5d5
Added tests to verify account can be used to publish presence

Ignore-this: eeeb4addec2c0b75d041496b89b67fea

darcs-hash:20090331114753-1e3d8-0f398c1683489ebcbf58594874c26b434d2a8e62