Depend on subversion-tools (<= 1.6.18dfsg-1) *or* svn2cl

svn2cl is no longer available in the unstable version of
subversion-tools, instead it's provided as separate package
as of subversion-tools 1.7.5-1.

Closes #45
use a more sensible default for DEBEMAIL
puppet: allow DEB_* environment variables in sudo configuration

Related to issue #46
puppet: use wget instead of curl as fallback for public IP retrieval

curl isn't present on Debian's AMI out-of-the-box.
puppet: do not install xunit plugin by default

Junit is available out-of-the-box in Jenkins and our configuration
actually uses that, so there's no point in installing the xunit
plugin by default.

Verified on fresh Ubuntu 12.04 EC2 system.

Thanks: Sylvestre Ledru <sylvestre.ledru@scilab-enterprises.com>
for bringing this up in https://github.com/mika/jenkins-debian-glue.org/pull/4
Bugfix: Make dpkg-source ignore .git in more cases

In some cases the '-I' param to dpkg-source is not enough. In this case
builds fail since dpkg-source complains about modified files.
This additionally adds (previously used) '-i' to the params, which
fixes those cases.
Merge pull request #52 from credativ/bugfix/dpkg-source-not-ignoring-git

Bugfix: Make dpkg-source ignore .git in more cases
Change timestamp format used in version string

The timestamp YYYYMMDDhhmmss sorts equally well as unix timestamp and
yet it is much more usable for human beings.