[UPDATE] Security updates and fixes

Live at https://mine.oscoin.org for testing

 * Config changes
   * Moves csrf, twofactor and maxfailed sections+2 new config sections from global config into security.dist.inc.php
     * Local security config overrides dist config as the default
   * Simple config checker - Thanks @iAmShorty for testing and ideas
  * Moves all documentation to the wiki, yay
  * Local config overrides dist config for global #1571 #1587
 * Adds options in security config to
   * Shim mysqli and run php filters against incoming data
   * Redirect to ssl pages sitewide

 * Misc
   * Displays last login IP/time in a popup on login, with close button

 * Rate limiting requests, which is enabled by default:
   * Adds the ability to limit the number of requests from the same IP down to X requests per Y time
   * Uses Memcache; no DB hits
   * This should cut down on some of the resource intensive pages being abused
   * Defaults protect everything and limit requests to 30 per 1 minute for site, 20 per 1 minute for api
   * Allows you to set a custom error page