create_local_branch: make check for remotes/origin/$BRANCH more explicit

We we can't do just a grep for "remotes/origin/debian when"
trying to check out the "debian" branch, instead we need to
check for a trailing '$' at the end of the grep string to
avoid matching e.g. remotes/origin/debian-lenny then.

Thanks: Axel Beckert
Do not execute dist_and_arch_settings() if PROVIDE_ONLY is set

There's no need to report what settings would be chosen for
executing cowbuilder if we're interested only in the
repository step, so just skip the code then.
git-buildpackage refuse to operate on a single git commit, too

Not only git-dch, but (now?) also git-buildpackage refuses to operate
on a single git commit, too, so remove the temporary branch later in
the workflow, after git-buildpackage has been called.
Fix README about DCH_OPTS and DCH_EXTRA_OPTS
Document how to find console output of Jenkins jobs

This is the leading FAQ, especially for Matrix configurations
so let's document it.
README: modify path for images to hopefully work on Github

Git-Dch: Ignore
README: hardcode image URLs to fix 404 for images on Github :(

Github, you suck at org-mode...

Git-Dch: Ignore
Do not use Grml-specific defaults for DEBEMAIL and generate-local-repository's Release file

Thanks to Axel Beckert <abe@deuxchevaux.org> for bringing this up
Update documentation to clarify best practices, current development + cover some FAQs, closes #9
Adjust identify_sourcefile to not mention ArtifactDeployer any longer

ArtifactDeployer isn't the preferred choice any longer nowadays
(it's "Copy Artifact Plugin" instead), so do not mention it.
README: minor syntax fixes and rewordings
Drop the deprecated scripts generate-local-repository + include-in-repos

I do not want to support anything other than reprepro for
repository handling and if someone needs a simpler solution than
reprepro it should be a no-brainer anyways.

include-in-repos on the other side was the idea to split
build-and-provide-package into a build and repository only step
for scaling the build pipeline. Nowadays we also do support
BUILD_ONLY and PROVIDE_ONLY inside build-and-provide-package, so
there is no reason to duplicate that code any longer.

Stuff from include-in-repos which turned out to be useful and
if we should ever need it again it's available inside git log to
easier stumble upon it:
* reprepro includedsc
* iff section/priority is empty then reprepro will complain
  about "No section and no priority for" and error out in the
  cmdline above, therefore we retry with -S and -P being set
  ${SUDO_CMD:-} reprepro -v -S unstable -P extra -b "${REPOSITORY}" …
arch:all packages don't need ${shlibs:Depends}

Fixes dpkg-gencontrol warning "Depends field of package
jenkins-debian-glue...: unknown substitution variable
${shlibs:Depends}".
Apply wrap-and-sort on Debian package
debian package description: fix typo
Execute wrap-and-sort with -a option to wrap all {Build-,}Depends
Also remove source package from REPOS
Set ARCH/BASE/DIST in dist_and_arch_settings() also for PROVIDE_ONLY runs
Limit package removal of binary packages to .deb files only

In the dcmd(1) listing there are also dsc, tar.XX and changes files
included, no need to run the binary removal for them as they either
don't exist or are duplicates.
remove_missing_binary_packages: make check for missing package match whole words

If we have a package named ngcp-templates-ce-hylafaxplus then
this will match within the string ngcp-templates-ce-hylafaxplus-iax
and therefore will be skipped as in the missing_packages list.
So make the grep match only leading and trailing white space characters.