Fix Makefile to be idempotent

Previously it failed on already existing symlinks.
Add missing dctrl-tools build dependency

Makefile is calling grep-dctrl.
Makefile: Don't call "checkdeps" on "make check"

The test suite doesn't actually need autopkgtest or the libjs packages (which
are for the UI only).
test/test_helper.sh: Don't hardcode "amd64"

This fixes test failure when building on other architectures. E. g. Ubuntu
builds "Architecture: all" packages on i386.
debci-generate-index: update packages.json atomically
utility functions to deal with maintainers
search: remove limit of number of items to display
trigger search immediately when there is text in the search box
group web UI improvement changelog entries
store search query in the URL, and honor that on new pages
Release to unstable
Fix documentation build
repository_spec: fix tmpdir location

Discovered this because I had /tmp/foobar created by root on my local
system for some unrelated tests. :-)
Handle invalid JSON data files
README.md: add missing `---` in example command line
lib/functions.sh: accept any value of Testsuite matching `autopkgtest`
Ensure that a package is listed under the correct prefix

The package prefix listing of 'l' contained packages that
should only be listed under a 'lib*' prefix.
update changelog
Prepare changelog for upload
Debci::Status#from_data: Support the older test data

The older test data did not contain 'run_id'. This caused broken
links to the older debci and test logs on a package's history page.