* version 0.8.10
  - try authentication with empty password instead of username if no
    password is given
  - support to read SIP message from standard input (-f -)
  - insert missing CR in front of LF (-L)
  - use different username for authentication (-u)
  - use multiple processes for usrloc, message and invite mode (-P)
  - search for a string in the reply with a regular expression (-q)
* version 0.8.10
  - send instant messages (just -M)
  - RFC 3261 compliant retransmission timer
  - added From (and To) tags
  - use MD5 from openssl if available
  - 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
  - use a raw socket if available to support broken RFC 3581 implementations
  - small fixes and betaufications
* version 0.8.9
  - added Nagios compliant exit codes
  - fixed missing replies from un-symmetric servers
  - added outbound proxy option
  - fixed SIP issues (CSeq increasement on authorization and added missing To and From tags)
* version 0.8.8
  - added -p option to use an outbound proxy
  - added -C option to use given Contact in REGISTER
  - fixed authentication failure when password given as last option
* version 0.8.7
  - merged listening and sending socket into one
  - added rport parameter to all Via lines
  - improved error reporting on host name resolving problems
* version 0.8.6
  - fixed wrong number of retries and timeouts from configure
  - fixed missing username in default mode
* version 0.8.5
  - seperated code into several files
  - introduced autoconf & automake
  - added option -o for sleeping between requests
  - added option -H to overwrite automatic hostname detection
  - ignores provisional responses in usrloc mode
  - added support for proxy authorization (407)
  - fixed missing port from uri in requests
  - number of retrys is configure option
  - maximum timeout value is configure option
