Internal executor, test framework, default path, test import enhancements...

• Correctly handle framework for new plans and tests
• Move runtest.sh adjustments into a single function
• Add the executable permission to runtest.sh
• Less strict removing sourcing of rhts-environment
• Use metadata directory as the default for path
• Implement the new L1 attribute 'framework'
• Explicitly enable copr_build for pull requests
• Handle missing library in existing repository
• Update the overall tmt description and examples
• Enable builds from master in the main copr repo
• Merge packit config for copr builds from master
• Use packit repository for copr builds from master
• Gracefully handle invalid test output
• Build in COPR for master via packit
• Add hint about caching the dnf package metadata
• Add two hints about easy login for experimenting
• Merge debug messages for the minute plugin [#361]
• Adjust the minute provision debug messages wording
• Use the internal tmt executor by default
• Add more debug messages to minute provision
• Remove the remaining 'tmt test convert' references
• Prevent shebang mangling for detached executor
• Merge the minute and install plugin docs [#345]
• Adjust the minute and install plugin documentation
• Merge the manual test import documentation [#347]
• Adjust the manual test documentation wording
• Merge rhts-environment source line removal [#344]
• Adjust rhts-environment source line removal
• Add missing extra-* keys to the test import
• Add docs for manual case import
• Disable authentication when fetching libraries
• Document the install prepare method
• Document the minute provision method
• Remove sourcing of rhts-environment in runtest.sh
• Add minute to supported provision methods of prepare