This got lost during the move, as the .gitignore from the index overrode
the on-disk contents.

- Move dpkg-deb and dpkg-split under src/ as these are part of the dpkg
  toolset.
- Move common source files under src/common/.
- Move program specific source files under subdirectories in src/.
- Rename the various *cmd.c into <tool>/main.c.
- Set automake option subdir-objects.

This makes it possible to embed libcompat inside libdpkg, so that the
static library that we ship is self contained with the required
compatibility code, specifically the MD5 functions.

This also prepares the build system for when we start building a
shared library, although it disables it by default.

Closes: #746122

Generating these at check time causes several problems. It requires a
system supporting versioned symbols and a GNU ld command line compatible
linker. Those are not available for example on Mac OS X.

Using libtool could have been an option to portably build the shared
libraries, although that still does not provide versioned symbols where
they are not available. The problem with libtool is that there's no sane
way to refer to the actual built shared library on the build tree.

Introduce a refresh-test-data target to be able to easily regenerate
those files when needed, e.g. when the test suite changes.

Reported-by: Stuart Ambler <stuart@zulazon.com>

This will allow setting local variables there instead of having to type
them everytime on the command line, or having to set them permanently on
the environment.

Enable code coverage support with 'configure --enable-coverage'. Use
gcov and lcov for C code coverage, and Devel::Cover and cover for Perl
code coverage.

Makes the directory name less confusing.

Keep the old ChangeLog files as ChangeLog.old, and distribute them.
Automatically genereate the ChangeLog from “git log”. And update the
information for translators.

Move common ignore matches to the top-level .gitignore.
Force directory matching by adding a trailing /.
Remove unused matches (enoent).
Add missing matches (t.tmp and autom4te.cache/).

This reverts commit e6164373.
Those directories are not supposed to exist any more, there's
no need to ignore them.

When porting to other systems without gettext functionality, other
applications might need it as well, so either use --with-libintl-prefix
for a global library, or disable NLS support.