pluggable representations, compressor pools

A summary of the bigger changes:

• WriteHeader done right (the only API change)
• Customizable encoding using EntityReaderWriter registration
• Customizable gzip/deflate readers and writers using CompressorProvider registration
• Swagger model from struct improvements (including arrays, more primitives, tags)
• Customizable logging
• many fixes

I want to thank all contributors to make this package as it is today.

Anastasis Andronidis,Artashes Aghajanyan,Brendan Burns,CL Sung,Chao Xu,Chris Broglie,Christian Muehlhaeuser,Clayton Coleman,Colin Henry,Daniel Seither,Derek Perkins,Donovan Kolbly,Gabor Nagy,Garrett D'Amore,George Adams, IV,Gerben Jacobs,Guy Morgan,James Adam,Jeff Mitchell,John Korb,Jordan Liggitt,Kazuki Suda,Marcin Tojek,Markus Boese,Nainterceptor,Nathan Johnson,Orne Brocaar,Porjo,Quinn Slack,Richard Kruspe,Steffen Neubauer,Stephen Hitchner,Travis Cline,Victor,Victor Blomqvist,Viktor Stanchev,Vyacheslav Bakhmutov,Wojciech Bederski,Yasser Abdolmaleki,Zack Owens,denistoikka,ivan,jaemin,jchenry,nikhiljindal,nullbus,oursky d,roland,runner.mei,taylorchu,thesyncim,Łukasz Kurowski

git log --all --format='%cN' | sort -u | tr "\n" ","

Shameless plug: Did you know about the https://github.com/emicklei/forest package to support automated tests of your REST api? See also http://ernestmicklei.com/2015/07/04/testing-your-rest-api-in-go-with-forest/

wildcard fix

Due to some incorrect unit tests, a bug was hidden in the implementation of wildcard usage in CurlyRouter.