dispatch: extract maybe-use-repr formatting to helper function
I think this makes the code much clearer. I had to think for a bit to
unpack the old-school `condition and if-true or if-false` dance, and
formatting argument lists here shouldn't be performance critical.
FROM centos:centos5
RUN yum install -y gcc make rpm-build gettext tar
RUN yum install -y python-devel python-docutils
# For creating repo meta data
RUN yum install -y createrepo
RUN yum install -y readline-devel openssl-devel ncurses-devel zlib-devel bzip2-devel