xcompmgr 1.1.9

• gitlab CI: add a basic build test
• Build xz tarballs instead of bzip2
• xcompmgr.man: Update bug reporting URL from bugzilla to gitlab
• Reduce variable scope as suggested by cppcheck
• Remove obsolete casts on malloc & free calls
• gitlab CI: stop requiring Signed-off-by in commits
• Resolve -Wshadow warnings
• Mark usage() as _X_COLD _X_NORETURN
• Remove unused macros