anchor.diff:  *   upgrade library deps
   *   various bug fixes
   
  -== 0.4.0 - 2014-05-23
  +== v0.4.0 - 2014-05-23
   
   *   remove config support (use env or cli flags)
   *   turn allowlist into a cli flag to parse a plain text file vs json config
   *   clean ups/general code hygiene
   
  -== 0.3.0 - 2014-05-13
  +== v0.3.0 - 2014-05-13
   
   *   Transparent base64 url support
   
  -== 0.2.0 - 2014-04-17
  +== v0.2.0 - 2014-04-17
   
   *   Remove NoFollowRedirects and add MaxRedirects
   *   Use https://github.com/mreiferson/go-httpclient to handle timeouts more
       cleanly
   
  -== 0.1.3 - 2013-06-24
  +== v0.1.3 - 2013-06-24
   
   *   fix bug in loop prevention
   *   bump max idle conn count
   *   keep idle conn trimmer running
   
  -== 0.1.2 - 2013-03-30
  +== v0.1.2 - 2013-03-30
   
   *   Add ReadTimeout to http.Server, to close excessive keepalive goroutines
   
  -== 0.1.1 - 2013-02-27
  +== v0.1.1 - 2013-02-27
   
   *   optimize date header generation to use a ticker
   *   performance improvements
   *   fix a few subtle race conditions with stats
   
  -== 0.1.0 - 2013-01-19
  +== v0.1.0 - 2013-01-19
   
   *   Refactor logging a bit
   *   Move encoding functionality into a submodule to reduce import size (and
  
positive.code: *   X-Forwarded-For support
  *   Added more info to readme
  
  == 0.0.2 - 2012-07-12
  
  *   documentation cleanup
  *   code reorganization
  *   some cleanup of command flag text
  *   logging code simplification
  
  == 0.0.1 - 2012-07-07
  
  *   initial release
  
negative.code: *   more performant stats (replaced mutex with sync/atomic)
  *   fewer spawned goroutines when using stats
  
  == v1.0.5 - 2016-02-18
  
  *   Build release with go1.6
  *   Switch to building with gb
  
  == v1.0.4 - 2015-08-28
  
  *   Minor change for go1.5 with proxy timeout 504
  
  == v1.0.3 - 2015-04-25
  
  *   revert to stdlib http client
  
  == v1.0.2 - 2015-03-08
  
  *   fix issue with http date header generation
  
  == v1.0.1 - 2014-12-16
  
  *   optimization for allow-list checks
  *   keepalive options fix
  
  == v1.0.0 - 2014-06-22
  
  *   minor code organization changes
  *   fix for heroku build issue with example code
  
  == v0.6.0 - 2014-06-13
  
  *   use simple router instead of gorilla/mux to reduce overhead
      and increase performance.
  *   move some code from camo proxy into the simple router
  
  == v0.5.0 - 2014-06-02
  
  *   some minor changes to Makefile/building
  *   add support for HTTP HEAD requests
  