enhance: Add comprehensive .gitignore for deb-mock project

- Add mock-specific build artifacts (chroot/, mock-*, mockroot/)
- Include package build files (*.deb, *.changes, *.buildinfo)
- Add development tools (.coverage, .pytest_cache, .tox)
- Include system files (.DS_Store, Thumbs.db, ._*)
- Add temporary and backup files (*.tmp, *.bak, *.backup)
- Include local configuration overrides (config.local.yaml, .env.local)
- Add test artifacts and documentation builds
- Comprehensive coverage for Python build system project

This ensures build artifacts, chroot environments, and development
tools are properly ignored in version control.

docs/Release-Notes-1.4.16.md

@@ -0,0 +1,20 @@
+---
+layout: default
+title: Release Notes 1.4.16
+---
+
+Released on 2019-05-22.
+
+## Mock new features and bugfixes:
+
+- switch to python3 on el7
+- respect use_host_resolv config even with use_nspawn (praiskup@redhat.com)
+- Fix crash on non-ascii dnf log messages (bkorren@redhat.com)
+
+Following contributors contributed to this release:
+
+* Barak Korren
+* Miro Hrončok
+* Pavel Raiskup
+
+Thank you.