* version 0.8.11
  - try authentication with empty password instead of username if no
    password is given
  - support to read SIP message from standard input (-f -)
* version 0.8.10
  - send instant messages (just -M)
  - new argument -C to use any given contact value, even empty
  - support long options if available
  - support Nagios warn level with optional numbers of retransmissions
* version 0.8.6
  - important fixes
* version 0.8.5
  - ignores provisional responses in usrloc mode (-U)
  - added support for proxy authorization (407)
  - new argument -H overwrites automatic hostname detection
  - new argument -o introduces sleeping seconds before sending next request
  - number of retrys and maximum timeout values are configure options
