 fix: turning on gzip cleared Etag subscriber response header
 fix: channels incorrectly deleted when overwhelmed with connections
 feature: CORS support via OPTIONS request method response
 fix: file descriptor leak when restarting nginx via SIGHUP
 improve: concurrency for interprocess notifications
 refactor: completely encapsulated message store
 fix: slow memory leak introduced in 0.7
 fix: memory leak when not using message buffer
0.712 (Mar. 21 2014)
 fix: intermittently dropped long-polling connections on internal redirects
 fix: unable to proxy long-polling subscribers. (thanks wandenberg and sanmai)
0.711 (Mar. 13 2014)
 fix: incompatibility with cache manager (proxy_cache and fastcgi_cache directives)
0.71 (Mar. 1 2014)
 fix: removed unused variables and functions to quiet down GCC
0.7: (Feb. 20 2014)
 fix: last-in concurrency setting wasn't working reliably
 refactor: partially separated message storage. add a test harness.
 fix: segfault from concurrency bug while garbage-collecting channels
 fix: some large messages got lost
0.692 (Feb. 3 2010)
 fix: error log reported failed close() for some publisher requests with large messages
 fix: occasional memory leak during message deletion
 fix: worker messages intended for dead worker processes were not deleted
0.691 (Feb. 2 2010)
 fix: server reload (via SIGHUP signal) was failing
 fix: segfault on messages longer than client_body_buffer_size (thanks wfelipe)
 change: removed push_min_message_recipients, added push_delete_oldest_received_message
0.69 (Nov. 17 2009)
 fix: publisher got a 201 Created response even if the channel had no subscribers at the time (should be 202 Accepted)
 fix: small memory leak after each message broadcast to a channel
 feature: optional push_max_channel_subscribers setting added
 fix: first-in concurrency setting wasn't responding to subscribers with a correct status code on conflict
 fix: reused subscriber connections sometimes failed to receive messages
 unfeature: no more nginx 0.6 support. not worth the hassle.
0.683 (Nov. 10 2009)
 change: default max. reserved memory size changed form 16MB to 32 MB
 change: unused node garbage collection made a little more aggressive (max. 3 unused channels per channel search instead of 1)
 fix: unused nodes were deleted only on channel id hash collision (very rare)
 fix: segmentation fault from allocating insufficient memory for interprocess messaging
0.681 (Nov. 6 2009)
 feature: added push_message_buffer_length setting, which sets push_message_max_buffer_length and push_message_min_buffer_length at once.
 fix: publisher channel info text/json response now uses double quotes instead of single.
 fix: interprocess messages were not removed from shared memory correctly, causing weird errors
0.68 (Nov. 5 2009)
 change: default push_subscriber_concurrency value is now "broadcast"
 fix: incorrect error messages for invalid push_pubscriber and push_subscriber_concurrency settings
 change: removed deprecated push_buffer_size and push_queue_messages settings
 feature: rudimentary content-type negotiation for publisher channel info response.
   support text/plain, text/json, text/yaml and application/xml (and mimetype equivalents)
 fix: publisher GET response has HTTP status 0
0.67beta (Nov. 4 2009) and older
 see git repository
