Remove the code responsible for implicitly compressing manpages as .gz
files. It has been established that manpage compression is a distro
packager's task, with existing distros already having their own
implementations of compression.
Fixes#4330
Add test to verify the installation of broken symlinks when a default_umask
is set.
Reusing the same code of other test, thus sharing the actual test code
in a single function.
This is a simple test case, checking for installed_files.txt, which just
makes sure the syntax is accepted.
Manual tests confirmed the permissions were set correctly.
A follow up commit adds a unit test based on this directory.