More updates to aid bug report processing

* Updated bugSplit.js to latest ve output + added charset to
  diff and message.

* Added fetch.js to fetch wikitext for a rev-id.

* Added process_bug_report.sh to run selser on a bug report
  with the latest codebase to check if the problem has been fixed.

Change-Id: I01478633608052689c09a2c2117d436e71391786
Merge "More updates to aid bug report processing"