idle: use the TpAccount pointer as key to the hash table, and remove values on disconnect
idle: use the TpAccount pointer as key to the hash table, and remove values on disconnect

https://bugzilla.gnome.org/show_bug.cgi?id=599169#c2

Signed-off-by: Jonny Lamb <54cd04502facfcf96b325c60af9b1611ee761860@gnome.org>

GNOME/telepathy-account-widgets,GNOME/telepathy-account-widgets,Distrotech/telepathy-account-widgets,GNOME/telepathy-account-widgets,Distrotech/telepathy-account-widgets