Sync (almost) all Jenkins config

Summary:
There are many changed files but the most important are
fetch_jenkins_config.exclude and fetch_jenkins_config.sh

The configuration files are mostly new files that we didn't previously
track. Most of the config isn't useful, it is simply default values,
with the exception of the global GIT user settings.

Test Plan:
I ran the new fetch script and verified that it picked up the config
changes I expected (mostly just creating files we weren't previously
tracking) and omitted files listed in the exclude file.

  $ ./fetch_jenkins_config.sh

Reviewers: csilvers

Reviewed By: csilvers

CC: desmond

Differential Revision: http://phabricator.khanacademy.org/D2718