1145723 - log startup message in Celery logs

On RHEL6, Pulp's init.d scripts invoke celery in a way that creates log files
under `/var/log/pulp/` that are not used during normal operation. This causes
confusion for users since they think the logs are going to be there instead of
to `/var/log/messages`.

The init.d scripts have been modified to print startup messages in these logs,
and direct users to `/var/log/messages` for more information.

I did not add "startup" to the log filenames in case a user is already
collecting logs from their existing locations.
Add some docs for new contributors
Merge pull request #1275 from beav/devdoc

Add some docs for new contributors
Merge pull request #1259 from beav/init.d-logging

1145723 - log worker startup/shutdown messages in Celery logs
Merge remote-tracking branch 'origin/2.5-dev'
Explicitly prompt user when disabling SELinux using dev-setup script.
Report number of catalog entries deleted; fix catalog url.
1127817 - return a 404 for consumer history request if consumer id does not exist
Clarify tagging process and ressurect tag.sh for use with nonrelease builds
Merge pull request #1282 from asmacdo/improve-build-docs

Clarify tagging process and ressurect tag.sh for use with nonrelease builds
1160796 - Allow TCP connections to all hosts and ports
Merge pull request #1283 from jortel/catalog-delete-command

Report number of catalog entries deleted; fix catalog url.
root directory style cleanup
Merge pull request #1288 from asmacdo/style-cleanup-rootdir

root directory style cleanup
resolve merge conflicts
Merge pull request #1289 from bmbouter/1160796

1160796 - SELinux change allowing celery to make TCP connections to all hosts and ports
Merge branch '2.5-testing' into 2.5-dev
Merge branch '2.5-dev'
add section about build tools
Merge pull request #1276 from beav/building-concepts

add section about build tools