Fmf

- Implement the new 'fmf clean' command
- Functions to manipulate cache
- Fetch the whole tree using utils.fetch_tree()
- Raise FileException on duplicate YAML keys
- Allow to set desired cache location
- Adjust support for storing modified data to disk
- Add support for storing modified metadata to disk
- Prevent exploring tests in the tmp directory
- Simplify special distro comparison examples
- Store command output in run(), fetch() exceptions
- Use filelock for locking, expand test coverage
- Adjust locking for Tree.node() and utils.fetch()
- Use locking to checkout/read tree
- Enable integration testing with tmt, some cleanup
- Implement a new method copy() for cloning nodes
- Adjust fetch() with custom destination and env
- Support calls fetch(destination, env) and run(env)
- Use the origin default branch instead of master
- Store commit hash if the tree is under a git repo

- Adjust context docs, fix typos, style cleanup
- Left vs Right side in Context matches
- Simplify deep merging, adjust test suite a bit
- Implement recursive merging of data
- Remove the duplicate build job from packit config
- Adjust 'make test' to work under virtualenv
- Update the adjust continue key default to True

- Enable copr builds from master, simplify config
- Adjust documentation for the new Context class
- Add documentation for the new Context class
- Add a new Tree.adjust() method for handling rules
- Context: Better operator names, comments
- Adjust the new Context implementation
- Context implementation

- Add git to BuildRequires (now required by tests)
- Use coveralls to report coverage results
- Adjust Tree.node() implementation, extend tests
- Get metadata for unique id [fix 67]
- Use the fedora-all target in packit config (72)
- Define the full fmf identifier [fix 52]
- A minor cleanup of the concept documentation
- Always ignore special system directories
- Filesystem root and inaccessible dirs [fix 70]
- Rename the 'testsets' directory to 'plans'

* Mock is not needed for docs, fix missing new line
* Provide a public static method Tree.init()
* Support custom conjunction like 'or' in listed()
* Update smoke testset to the latest L2 spec
* Fix build conditional default for englocale
* Use raw strings for regular expression patterns
* Update the list of supported Python versions