Add installation and packaging targets

[FelixKimmerle]

Since I completed the Optional Bonus Task, to test it you need to build the Docker container:

  sudo docker build -t cpack_ex .

and run it like this:

  sudo docker run --rm -v "$(pwd)":/src:ro -v "$(pwd)/dist":/out cpack_ex

This will build the packages (.tgz, .deb) and place them in the dist folder.
No build artifacts will be created on the host. The only caveat I noticed is that the files are owned by root, so you need sudo to delete them again.

When I initially ran lintian I got the following output:

  E: cpackexample: no-changelog usr/share/doc/cpackexample/changelog.gz (native package)
  E: cpackexample: no-copyright-file
  E: cpackexample: no-phrase Maintainer FelixKimmerle@hotmail.com
  E: cpackexample: unstripped-binary-or-object [usr/bin/cpackexample]
  W: cpackexample: no-manual-page [usr/bin/cpackexample]

I fixed all of them, so there was no output from lintian after the fixes.
For this I had to:

• install the repository’s LICENSE file into usr/share/doc/cpackexample/copyright (I used ${CMAKE_INSTALL_DOCDIR} from GNUInstallDirs)
• create, compress, and install a changelog (it has no useful content but abides by the convention so that lintian does not complain)
• create, compress, and install a man page (it also has no really useful content but serves as an example)
• enable stripping of the binaries
• format the Maintainer string to conform to the convention: Name <email>

Since the Optional Bonus Task asks to build the library as a shared library, there are now new things lintian is complaining about because I did not change anything else, and it wants the .deb package to contain ldconfig information and wants the name of the .so to include the version number:

  E: cpackexample: lacks-ldconfig-trigger usr/lib/libcpackexamplelib.so
  W: cpackexample: maintscript-calls-ldconfig [postinst]
  W: cpackexample: maintscript-calls-ldconfig [postrm]
  W: cpackexample: package-name-doesnt-match-sonames libcpackexamplelib
  W: cpackexample: shared-library-lacks-version usr/lib/libcpackexamplelib.so libcpackexamplelib.so

I used generative AI for the content of the changelog and the manpage.