Update to Fossil 1.22.

Update to Fossil 1.22.

Notable changes:

  * Greatly improved "diff" processing including the new --brief option,
    partial line matching, colorized in-line diffs, and better performance.
  * Promote "allow-symlinks" to a versionable setting
  * Harden the CGI processing logic against DOS attacks
  * Add the ability to run TH1 scripts after sync requests
  * Store the repository name in _FOSSIL_ as it is type in the "open" command,
    possibly as a relative pathname.
  * Make ".fslckout" the alternative name for the "_FOSSIL_" file.
  * Change the "ssh:" transfer method to allow all access regardless of
    user permission.
  * Improvements to the timeline messages associated with tag changes.
    (Requires a "fossil rebuild" to take effect.)
  * Various additions and fixes for the JSON API.
  * Improved merge-with-rename handling.
  * --cherrypick merges use their origin's commit message by default.
  * Added support for multiple concurrent logins per user.
  * Update to use SQLite version 3.7.11.
  * Various minor bug fixes.