add logging MSRP connection status

darcs-hash:20090115103718-b2873-c907bf675f4f890d2569a69cdaba03e06245758e
add "from pypjua import PyPJUAError" where it's needed

darcs-hash:20090115105533-b2873-a02241b176fcf1e37e2c0c25a07ff1488ded0b9b