Fix installation instructions for running gitlab_status

When running `rake gitlab_status` to check if it's safe to continue on installation in step 4, you need to use `RAILS_ENV=production` or else you will receive an error about "permission denied for user root@localhost..."

See https://github.com/gitlabhq/gitlabhq/issues/572

Conflicts:
	resque.sh

Use of -p option of mkdir command to avoid message telling tmp/pids directory already exists...

Use of -p option of mkdir command to avoid message telling tmp/pids directory already exists at every GitLab (re)start. It ensures that all directories on the path exists so it can create tmp directory if its not there for some reason.

Need to replace If statement with try_files in nginx.conf

http://wiki.nginx.org/IfIsEvil