Merge pull request #105 from caiiiycuk/master

Fix [ru] Add guide about installing DCEVM
#104 [3.18] Move routes.cache to tmp/routes.cache
Fix broken link: http://docs.jquery.com/Plugins/validation -> http://jqueryvalidation.org/
Fix broken link: https://github.com/JamesEarlDouglas -> https://github.com/earldouglas
Fix broken link: http://en.wikipedia.org/wiki/Comet_(programming)/ -> http://en.wikipedia.org/wiki/Comet_%28programming%29
Fix broken link: http://code.google.com/intl/en/speed/page-speed/docs/caching.html -> https://developers.google.com/speed/docs/best-practices/caching
Fix broken link: https://github.com/xitrum-framework/xitrum/blob/master/src/main/scala/xitrum/scope/request/ParamAccess.scala -> https://github.com/xitrum-framework/xitrum/blob/master/src/main/scala-2.11/xitrum/scope/request/ParamAccess.scala
Fix broken links to SessionStore.scala and ServerSessionStore.scala
Fix broken link: http://xitrum-framework.github.io/api/index.html -> http://xitrum-framework.github.io/api/3.17/index.html
Fix broken link: <http://xitrum-framework.github.io/guide/en/index.html -> <http://xitrum-framework.github.io/guide.html
Fix guide about extending xitrum.Log
Fix #108 Split "Log" from "HOWTO" to a separate chapter
Fix #107 [en] Add guide about logging to Fluentd
Fix #110 [ja] Add guide about logging to Fluentd
Fix issue#109 (Add guide about logging to Fluentd)